EXHIBIT 5.1

                               [Letterhead of CNA]


                               September 13, 2005



CNA Financial Corporation
CNA Center
Chicago, Illinois  60685

Ladies and Gentlemen:

         I am providing this opinion as Executive Vice President, General
Counsel and Secretary of CNA Financial Corporation, a Delaware corporation (the
"Company"), in connection with the preparation of the Registration Statement on
Form S-3 (Reg. No. 333-127544) (the "Registration Statement") filed with the
Securities and Exchange Commission (the "Commission") under the Securities Act
of 1933, as amended (the "Securities Act"), with respect to the contemplated
issuance by the Company from time to time of (i) unsecured senior debt
securities, subordinated debt securities and subordinated junior debt securities
(the "Debt Securities"), which may be issued pursuant to an Indenture, dated as
of March 1, 1991, between the Company and The First National Bank of Chicago, as
trustee, as supplemented by a first supplemental indenture, dated as of October
15, 1993, between the Company and The First National Bank of Chicago, as
trustee, and a second supplemental indenture, dated as of December 15, 2004,
between the Company and J. P. Morgan Trust Company, National Association
(formerly known as The First National Bank of Chicago), as trustee (as so
supplemented, the "Senior Indenture"), a Subordinated Indenture, as supplemented
from time to time, between the Company and J. P. Morgan Trust Company, National
Association, as trustee (as so supplemented, the "Subordinated Indenture") and a
Junior Subordinated Indenture, as supplemented from time to time, between the
Company and J. P. Morgan Trust Company, National Association, as trustee (as so
supplemented, the "Junior Subordinated Indenture" and, together with the Senior
Indenture and the Subordinated Indenture, the "Indentures"); (ii) shares of
preferred stock, no par value per share (the "Preferred Stock"), which may be
represented by depositary shares (the "Depositary Shares") evidenced by
depositary receipts (the "Receipts"); (iii) shares of common stock of the
Company, par value $2.50 per share (the "Common Stock"); (iv) warrants to
purchase any of the foregoing Debt Securities, Preferred Stock, Common Stock or
Depository Shares (the "Warrants"); (v) preferred securities (the "Trust
Preferred Securities") of CNA Financial Capital I, CNA Financial Capital II and
CNA Financial Capital III (each a "CNA Capital Trust" and, collectively, the
"CNA Capital Trusts"); (vi) purchase contracts ("Purchase Contracts") to
purchase any of the Debt Securities, Common Stock, Preferred Stock, Depository
Shares, Warrants and Trust Preferred Securities (collectively, the "Purchase
Contract Securities") or (vii) purchase units ("Purchase Units"), each
representing ownership





of a Purchase Contract and any of (x) Debt Securities, (y) debt obligations of
third parties, including treasury bonds or similar obligations of the U.S.
and/or (z) Trust Preferred Securities; and (viii) guarantees of the Company of
Trust Preferred Securities of the CNA Capital Trusts which may be issued
pursuant to guarantee agreements (the "Guarantee Agreements") to be executed by
the Company.

         I have examined originals or copies, certified or otherwise identified
to my satisfaction, of such documents, corporate records, certificates of public
officials and other instruments as I have deemed necessary for the purpose of
rendering this opinion. In addition, this opinion is based upon the assumption
that the Registration Statement and any required post-effective amendments
thereto have become effective under the Securities Act.

         On the basis of the foregoing I am of the opinion that:

         1. Assuming that the Indentures, any Debt Securities, and any Board
Resolution (as defined in the applicable Indenture) or supplemental indenture
with respect to the issuance of such Debt Securities have been duly authorized,
when (i) the Registration Statement has become effective under the Securities
Act; (ii) a Board Resolution or supplemental indenture in respect of the Debt
Securities has been duly authorized, executed and delivered; (iii) the terms of
the Debt Securities and of their issuance and sale have been duly established in
conformity with the applicable Indenture and the applicable Board Resolution or
supplemental indenture relating to such Debt Securities so as not to violate any
applicable law or result in a default under or breach of any agreement or
instrument binding upon the Company and so as to comply with any requirement or
restriction imposed by any court or governmental or regulatory body having
jurisdiction over the Company; and (iv) the Debt Securities have been duly
executed and authenticated in accordance with the applicable Indenture and the
applicable Board Resolution or supplemental indenture relating to such Debt
Securities, and duly issued, sold and paid for as contemplated by the
Registration Statement and any prospectus supplement relating thereto, the Debt
Securities (including any Debt Securities duly issued (x) upon the exchange or
conversion of any shares of Preferred Stock that are exchangeable or convertible
into Debt Securities, (y) upon exercise of any Warrants exercisable for Debt
Securities or (z) as part of Purchase Units) will constitute valid and legally
binding obligations of the Company enforceable in accordance with their terms,
subject to (a) bankruptcy, insolvency, reorganization, fraudulent transfer,
moratorium and other similar laws now or hereafter in effect relating to or
affecting creditors rights generally, (b) general principles of equity
(regardless of whether considered in a proceeding at law or in equity) and (c)
the qualification that the remedy of specific performance and injunctive and
other forms of equitable relief may be subject to equitable defenses and to the
discretion of the court before which any proceeding therefor may be brought.

         2. Assuming that a Deposit Agreement relating to the Depositary Shares
(the "Deposit Agreement") has been duly authorized, when (i) the Registration
Statement has become effective under the Securities Act; (ii) the Deposit
Agreement has been duly executed and delivered; (iii) the terms of the
Depositary Shares and of their issuance and




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sale have been duly established in conformity with the Deposit Agreement
relating to such Depositary Shares so as not to violate any applicable law or
result in a default under or breach of any agreement or instrument binding upon
the Company and so as to comply with any requirement or restriction imposed by
any court or governmental or regulatory body having jurisdiction over the
Company; (iv) the Preferred Stock has been duly and properly authorized for
issuance and a Certificate of Amendment to the Certificate of Incorporation of
the Company classifying the Preferred Stock and setting forth the terms thereof
has been filed and accepted for record; (v) such shares of Preferred Stock have
been duly issued, sold and paid for in the manner contemplated in the
Registration Statement and any prospectus supplement relating thereto; and (vi)
the Receipts evidencing the Depositary Shares are duly issued against the
deposit of the Preferred Stock in accordance with the Deposit Agreement, such
Receipts will be validly issued and will entitle the holders thereof to the
rights specified therein and in the Deposit Agreement.

         3. Assuming that a Warrant Agreement relating to the Warrants (the
"Warrant Agreement") has been duly authorized, when (i) the Registration
Statement has become effective under the Securities Act; (ii) the Warrant
Agreement has been duly executed and delivered; (iii) the terms of the Warrants
and of their issuance and sale have been duly established in conformity with the
Warrant Agreement relating to such Warrants so as not to violate any applicable
law or result in a default under or breach of any agreement or instrument
binding upon the Company and so as to comply with any requirement or restriction
imposed by any court or governmental or regulatory body having jurisdiction over
the Company; and (iv) the Warrants have been duly executed and countersigned in
accordance with the Warrant Agreement relating to such Warrants, and issued and
sold in the form and in the manner contemplated in the Registration Statement
and any prospectus supplement relating thereto, such Warrants will constitute
valid and legally binding obligations of the Company enforceable in accordance
with their terms, subject to (a) bankruptcy, insolvency, reorganization,
fraudulent transfer, moratorium and other similar laws now or hereafter in
effect relating to or affecting creditors' rights generally, (b) general
principles of equity (regardless of whether considered in a proceeding at law or
in equity) and (c) the qualification that the remedy of specific performance and
injunctive and other forms of equitable relief may be subject to equitable
defenses and to the discretion of the court before which any proceeding therefor
may be brought.

         4. When (i) the Registration Statement has become effective under the
Securities Act; (ii) the terms of the Preferred Stock have been duly and
properly authorized for issuance and a Certificate of Amendment to the
Certificate of Incorporation of the Company classifying the Preferred Stock and
setting forth the terms thereof has been filed; and (iii) such shares of
Preferred Stock have been duly issued, sold and paid for in the manner
contemplated in the Registration Statement and any prospectus supplement
relating thereto, such shares of Preferred Stock will be validly issued, fully
paid and nonassessable.

         5. When (i) the Registration Statement has become effective under the
Securities Act; (ii) the shares of Common Stock have been duly and properly
authorized




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for issuance; and (iii) the shares of Common Stock have been duly issued, sold
and paid for as contemplated in the Registration Statement and any prospectus
supplement relating thereto, the shares of Common Stock (including any Common
Stock duly issued (w) upon the exchange or conversion of any shares of Preferred
Stock that are exchangeable or convertible into Common Stock, (x) upon the
exercise of any Warrants exercisable for Common Stock, (y) upon the conversion
or exchange of any Debt Securities that are convertible or exchangeable into
Common Stock or (z) pursuant to Purchase Contracts), will be validly issued,
fully paid and nonassessable.

         6. Assuming that a Purchase Contract Agreement relating to the Purchase
Contracts (the "Purchase Contract Agreement") and such Purchase Contracts have
been duly authorized, when (i) the Registration Statement has become effective
under the Securities Act; (ii) the Purchase Contract Agreement has been duly
executed and delivered; (iii) the terms of the Purchase Contracts have been duly
established so as not to violate any applicable law or result in a default under
or breach of any agreement or instrument binding upon the Company and so as to
comply with any requirement or restriction imposed by any court or governmental
or regulatory body having jurisdiction over the Company; (iv) the Purchase
Contracts have been duly executed and issued in accordance with the Purchase
Contract Agreement relating to such Purchase Contracts, and issued and sold in
the form and in the manner contemplated in the Registration Statement and any
prospectus supplement relating thereto, such Purchase Contracts will constitute
valid and binding obligations of the Company, enforceable in accordance with
their terms, subject to (a) bankruptcy, insolvency, reorganization, fraudulent
transfer, moratorium and other similar laws now or hereafter in effect relating
to or affecting creditors' rights generally, (b) general principles of equity
(regardless of whether considered in a proceeding at law or in equity) and (c)
the qualification that the remedy of specific performance and injunctive and
other forms of equitable relief may be subject to equitable defenses and to the
discretion of the court before which any proceeding therefor may be brought.

         7. Assuming that the Purchase Units, a Purchase Contract Agreement
relating to the Purchase Contracts comprising a part of the Purchase Units and
such Purchase Contracts have been duly authorized, when (i) the Registration
Statement has become effective under the Securities Act; (ii) the Purchase
Contract Agreement has been duly executed and delivered; (iii) the terms of the
Purchase Contracts and of their issuance and sale have been duly established in
conformity with the Purchase Contract Agreement so as not to violate any
applicable law or result in a default under or breach of any agreement or
instrument binding upon the Company and so as to comply with any requirement or
restriction imposed by any court or governmental or regulatory body having
jurisdiction over the Company; (iv) the terms of the collateral arrangements
relating to such Purchase Units have been duly established and the agreement(s)
relating thereto has been duly executed and delivered, in each case so as not to
violate any applicable law or result in a default under or breach of any
agreement or instrument binding upon the Company and so as to comply with any
requirement or restriction imposed by any court or governmental or regulatory
body having jurisdiction over the Company, and the collateral has been deposited
with the collateral agent in accordance with such arrangements; and (v) the
Purchase Contracts have been duly executed and




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issued in accordance with the Purchase Contract Agreement relating to such
Purchase Contracts, and issued and sold in the form and in the manner
contemplated in the Registration Statement and any prospectus supplement
relating thereto, such Purchase Units will constitute valid and binding
obligations of the Company, enforceable in accordance with their terms, subject
to (a) bankruptcy, insolvency, reorganization, fraudulent transfer, moratorium
and other similar laws now or hereafter in effect relating to or affecting
creditors' rights generally, (b) general principles of equity (regardless of
whether considered in a proceeding at law or in equity) and (c) the
qualification that the remedy of specific performance and injunctive and other
forms of equitable relief may be subject to equitable defenses and to the
discretion of the court before which any proceeding therefor may be brought.

         8. Assuming that the Guarantees have been duly authorized, when (i) the
Registration Statement has become effective under the Securities Act; (ii) the
applicable Guarantee Agreement has been duly executed and delivered, so as not
to violate any applicable law or result in a default under or breach of any
agreement or instrument binding upon the Company and so as to comply with any
requirement or restriction imposed by any court or governmental or regulatory
body having jurisdiction over the Company; and (iii) the Trust Preferred
Securities have been duly issued and delivered by the applicable CNA Capital
Trust as contemplated by the Registration Statement and any prospectus
supplement relating thereto, the Guarantees will constitute valid and legally
binding obligations of the Company, enforceable in accordance with their terms,
subject to (a) bankruptcy, insolvency, reorganization, fraudulent transfer,
moratorium and other similar laws now or hereafter in effect relating to or
affecting creditors' rights generally, (b) general principles of equity
(regardless of whether considered in a proceeding at law or in equity) and (c)
the qualification that the remedy of specific performance and injunctive and
other forms of equitable relief may be subject to equitable defenses and to the
discretion of the court before which any proceeding therefor may be brought.

         This opinion is limited to the federal laws of the United States of
America, the laws of the States of New York and Illinois and Delaware General
Corporation Law. This opinion is limited in all respects to the laws and facts
existing on the date hereof. I hereby consent to the filing of this opinion as
Exhibit 5.1 to the Registration Statement and to the reference to my name under
the caption "Validity of Securities" in the Prospectus constituting a part
thereof, as originally filed or as subsequently amended or supplemented. This
opinion may not be relied upon by you for any other purpose, or relied upon by
any other person, firm or corporation or quoted, filed with any governmental
authority or other regulatory agency or otherwise circulated or utilized for any
other purpose without my prior written consent.

                                                   Very truly yours,

                                                   /s/ Jonathan D. Kantor

                                                   Jonathan D. Kantor, Esq.
                                                   Executive Vice President,
                                                   General Counsel and Secretary


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