The present invention is directed to aqueous bivalirudin compositions and methods of administration of such compositions. The aqueous bivalirudin compositions of the present invention have a pH of about 3 to about 5 and are substantially free of buffer. Further compositions of the present invention include bivalirudin compositions comprising at least one stabilizer having a pH of about 3 to about 5. Additional compositions of the present invention include bivalirudin compositions comprising at least one stabilizer substantially free of buffer. Compositions of the present invention also include bivalirudin compositions substantially free of buffer. The invention is also directed to methods of treatment comprising administering a bivalirudin composition of the present invention. The invention is further directed to the use of the bivalirudin compositions of the present invention as an anticoagulant in a patient in need thereof.