The aim of the present investigation was to establish the sperm antibody incidence among patients included in a program for assisted reproduction by the means of the classical and new methods for sperm antibody detection; to analyze the correlation between the results demonstrated by the different techniques; to evaluate the obtained data in the context of the application of new assisted reproduction technologies (ART). In the Laboratory of Reproductive Immunology, Department of Biology, Medical University of Sofia, 73 sera from patients (35 couples and 3 men) with primary and secondary infertility, aged 23-46 years, grouped according to the diagnosis and included in the program for assisted reproduction "Technobioassistance" were tested. Our results demonstrated the highest incidence of sperm antibodies amongst patients with primary unexplained infertility. The percentage of positive reacting couples for at least one of the applied tests was 31%. The highest relative share of those reacting positively, was observed with ELISA and the tray agglutination test (TAT) of Friberg. For ELISA 31.48% of the sera reacted positively, while clinically relevant liters of sperm antibodies were found with TAT in 21.92% of the tested sera. We also found that 17.46% and 13.7% of the tested sera were positive, respectively in the sperm immobilization test (SIT) of Isojima and the gelatin agglutination test (GAT) of Kibrick. The high degree of correlation (P < 0.0001) between the tests of Kibrick and Friberg showed the appropriateness of their application for patients in an ART program. At the other hand, the lack of correlation between the other applied tests (the Isojima test and ELISA) confirmed the assumption that immunity against spermatozoa should be sought with at least two diagnostic tools. Five of the tested families with clinically relevant TAT titers were included in our ART program for "in vitro" fertilization and embryo transfer, after preliminary absorption of the seminal fluid with autologous semen, or underwent the ICSI technique. For these patients, one ICSI pregnancy finished with the successful birth of a healthy child and one "in vitro" pregnancy is developing at the moment.