As filed with the Securities and Exchange Commission on February 24, 2004

1110 Spring Street
Silver Spring, MD 20910
(301) 608-9292
(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)
———————
Martine A. Rothblatt
Chairman and Chief Executive Officer
United Therapeutics Corporation
1110 Spring Street
Silver Spring, MD 20910
(301) 608-9292
(Name, Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent For Service)
———————
Copies to:
Paul A. Mahon
Senior Vice President and General Counsel
United Therapeutics Corporation
1110 Spring Street
Silver Spring, MD 20910
(301) 608-9292

Approximate date of commencement of proposed sale of the securities to the public: Not applicable.

If any of the securities being registered on this form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.      

If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.      

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.      

If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.      

If delivery of the prospectus is expected to be made pursuant to Rule 434, please check the following box.      

EXPLANATORY STATEMENT

     Pursuant to this Post-Effective Amendment to its Registration Statement on Form S-3, as amended (Registration No. 333-41866), United Therapeutics Corporation deregisters all shares of its common stock, par value $0.01 per share, heretofore registered and not previously sold.

SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Silver Spring, County of Montgomery, State of Maryland on the 23rd day of February, 2004.

     Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed below by the following persons in the capacities and on the dates stated.