Reproductive failure and anti-sperm antibody (ASA) production among prostitutes were investigated. A questionnaire including the subject's age, years of prostitution, date of most recent birth, number of children and contraceptive method used at the beginning of prostitution were asked of 109 prostitutes, but only 53 agreed to complete the questionnaire. ASA was detected by ELlSA in the prostitutes (n=109) and in the control group (n=40) sera. The tests revealed a high ASA rate (43.1%) among the prostitutes. The difference in the incidence of ASA between controls (5%) and the prostitutes (43.1%) was highly significant (p < 0.01). It was found that ASA positivity incidence in 27 prostitutes who had never use any contraception method and who became infertile within 9,3 years (average) was 61.3%. These results may be explained by repeatedly inoculations with multiple sperm antigens and/or microorganisms.