Administration of longidaza at a dose of 3000 IU intramuscularly twice a week after 1 month of treatment leads to the statistically significant reduction of antisperm antibodies (ASAB) at the surface of sperm cells to 23% (7-48%) for MARIgG and to 14.5% (3-34%) for MARIgA. Maximum reduction of ASAB, however, was observed after third month of treatment, mean MARIgG was 2% (1-26,5%) and MARIgA - 1% (0-11.5%). ASAB level has not reduced less than 50% only in one patient (1.67%). At follow-up three months after the cancellation of Longidaza, only 17 (28.33%) men showed an increase of ASAB IgG and (or) IgA more than 50%. Inthe study group, during the observation, spontaneous pregnancy occurred in 6 (10%) pairs, and IVF was successfully performed in 3 (5%) pairs. Thus, we consider it necessary to appoint Longidaza in patients with category 4 chronic prostatitis and elevated levels of antisperm antibodies on sperm cells, who preparing for assisted reproductive technologies, or preparing for natural pregnancy, as a high-effective pathogenetical agent for the treatment of autoimmune infertility.