The results of the clinical trials of human recombinant interferon alpha-2 (reaferon) make it possible to come to the conclusion that the preparation is well-tolerated and produces a pronounced therapeutic effect in a number of viral and oncological diseases. The Pharmacological Committee of the USSR has recommended reaferon for use in acute hepatitis B, hairy cell leukemia, renal cancer at stage IV, disseminated sclerosis, ocular herpes. The use of reaferon has been found to be promising in the treatment of papillomatosis of the larynx, Kaposi's sarcoma, mycosis fungoides, chronic myeloleukemia.