EXHIBIT 5.1

                                                           [JENNER & BLOCK LOGO]

                                        Jenner & Block LLP
                                        One IBM Plaza             Chicago
                                        Chicago, IL 60611         Dallas
                                        Tel  312-222-9350         New York
December 22, 2006                       www.jenner.com            Washington, DC

Viskase Companies, Inc.
8205 South Cass Avenue, Suite 115
Darien, IL 60561

Ladies and Gentlemen:

         We have acted as special counsel to Viskase Companies, Inc., a Delaware
corporation (the "Company"), in connection with the Registration Statement on
Form S-1 (File No. 333-139145) (the "Registration Statement") filed by the
Company with the Securities and Exchange Commission (the "Commission") under the
Securities Act of 1933, as amended (the "Securities Act"), relating to the
issuance of (a) an aggregate of 12,307,692 rights (the "Rights") to purchase
common stock, par value $0.01 per share of the Company (the "Common Stock")
pursuant to a rights offering (the "Rights Offering") to stockholders of record
on the record date for the Rights Offering and (b) an aggregate of 12,307,692
shares of Common Stock issuable upon exercise of the Rights, in each case as
contemplated by the Registration Statement.

         We have examined the originals, or duplicates or certified or conformed
copies, of such records, agreements, instruments and other documents, including
the Registration Statement and the form of certificate representing the Rights,
and have made such other and further investigations as we have deemed relevant
and necessary in connection with the opinions expressed herein. As to questions
of fact material to this opinion, we have relied upon certificates of officers
and representatives of the Company.

         In rendering the opinions that follow, we have assumed: (i) the
genuineness of all signatures; (ii) the legal capacity of natural persons; (iii)
the authenticity of all documents submitted to us as originals; (iv) the
conformity to the original documents of all documents submitted to us as
duplicates or certified or conformed copies; and (v) the authenticity of the
originals of such latter documents.

         Based upon the foregoing, and subject to the qualifications and
limitations stated herein, we are of the opinion that the shares of Common Stock
issuable upon exercise of the Rights are duly authorized, and when such shares
are issued upon exercise of the Rights in accordance with their terms as
described in the Registration Statement, such shares will be legally issued,
fully paid and nonassessable.

         Our opinions set forth above are subject to the effects of: (1)
bankruptcy, insolvency, fraudulent conveyance, reorganization, moratorium and
other similar laws relating to or affecting



creditors' rights generally; (2) general equitable principles (whether
considered in a proceeding in equity or at law); (3) the implied covenant of
good faith and fair dealing; and (4) public policy.

         We do not express any opinion herein concerning any law other than the
General Corporation Law of the State of Delaware, the law of the State of
Illinois and the Federal law of the United States.

         We hereby consent to the filing of this letter as Exhibit 5.1 to the
Registration Statement and the use of our name under the caption "Legal Matters"
in the Prospectus included in the Registration Statement.



                                                           Very truly yours,



                                                           Jenner & Block LLP

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