Prospectus Supplement Filed pursuant to Rule 424(b)(3)

Registration No. 333-135018

PROSPECTUS SUPPLEMENT NO. 26

DATED SEPTEMBER 21, 2007

(To Prospectus Dated June 22, 2006)

ACCENTIA BIOPHARMACEUTICALS, INC.

2,470,500 Shares of Common Stock

This prospectus supplement supplements information contained in, and should be read in conjunction with, that certain Prospectus, dated June 22, 2006, of Accentia Biopharmaceuticals, Inc. (the “Company”) as supplemented by Supplement No. 25 thereto dated September 12, 2007, Supplement No. 24 thereto dated September 6, 2007, Supplement No. 23 thereto dated August 24, 2007, Supplement No. 22 thereto dated August 15, 2007, Supplement No. 21 thereto dated June 29, 2007, Supplement No. 20 thereto dated June 14, 2007, Supplement No. 19 thereto dated May 15, 2007, Supplement No. 18 thereto dated April 19, 2007, Supplement No. 17 thereto dated March 28, 2007, Supplement No. 16 thereto dated March 2, 2007, Supplement No. 15 thereto dated February 14, 2007*, Supplement No. 14 thereto dated January 29, 2007, Supplement No. 13 thereto dated January 19, 2007, Supplement No. 12 thereto dated December 29, 2006, Supplement No. 11 thereto dated December 14, 2006, Supplement No. 10 thereto dated November 15, 2006, Supplement No. 9 thereto dated November 6, 2006, Supplement No. 8 thereto dated November 3, 2006, Supplement No. 7 thereto dated October 20, 2006, Supplement No. 6 thereto dated October 2, 2006, Supplement No. 5 thereto dated September 26, 2006, Supplement No. 4 thereto dated September 12, 2006, Supplement No. 3 thereto dated August 29, 2006, Supplement No. 2 thereto dated August 24, 2006 and Supplement No. 1 thereto dated July 19, 2006. This prospectus supplement is not complete without, and may not be delivered or used except in connection with, the original Prospectus and Supplement Nos. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 and 25 thereto. The Prospectus relates to the public sale, from time to time, of up to 2,470,500 shares of our common stock by the selling shareholders identified in the Prospectus.

The information attached to this prospectus supplement modifies and supersedes, in part, the information in the Prospectus, as supplemented. Any information that is modified or superseded in the Prospectus shall not be deemed to constitute a part of the Prospectus, except as modified or superseded by this prospectus supplement or Prospectus Supplement Nos. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 and 25.

This prospectus supplement includes the attached Form 8-K dated September 21, 2007 as filed by us with the Securities and Exchange Commission.

We may amend or supplement the Prospectus from time to time by filing amendments or supplements as required. You should read the entire Prospectus and any amendments or supplements carefully before you make an investment decision.

The Securities and Exchange Commission and state securities regulators have not approved or disapproved these securities or determined if this Prospectus Supplement (or the original Prospectus dated June 22, 2006, as previously supplemented) is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is September 21, 2007.

* The prospectus supplement dated February 14, 2007 was misnumbered and should have been prospectus supplement no. 15.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): September 17, 2007

ACCENTIA BIOPHARMACEUTICALS, INC.

(Exact name of Registrant as Specified in its Charter)

Florida	000-51383	04-3639490
(State or other jurisdiction of incorporation or organization)	(Commission File Number)	(I.R.S. Employer Identification No.)

324 South Hyde Park Ave., Suite 350

Tampa, Florida 33606

(Address of Principal Executive Offices; Zip Code)

Registrant’s telephone number, including area code: (813) 864-2554

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2-(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

ACCENTIA BIOPHARMACEUTICALS, INC.

FORM 8-K

Item 8.01. Other Events.

On September 17, 2007 Accentia Biopharmaceuticals, Inc. (the “Company”) extended the exercise period of the short-term warrants (the “Warrants”) issued on February 28, 2007 in connection with the 8% Convertible Debenture Financing from September 17, 2007 through 5:00 P.M. Eastern time on September 28, 2007.

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Signature

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunder duly authorized.

ACCENTIA BIOPHARMACEUTICALS, INC.
By:	/s/ Samuel S. Duffey
	Samuel S. Duffey
	General Counsel

Date: September 21, 2007

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