A direct immunobead test (IBT) was performed on 233 men who attended an immunological centre. Thirty‐four (14.6%) of these men were found to be positive (>20% binding) for antisperm antibodies (ASA). IgA, IgG and IgM were the most common sperm‐associated immunoglobulins. In 50% of men with ASA astheno‐zoospermia, teratozoospermia, leukocytospermia or hypofunction of the seminal vesicles was observed. Semen parameters were altered most frequently when IgM was present in association with IgA and/or IgG. This suggests that there is an active inflammatory process in the reproductive tract, as evidenced by leukocytospermia, and this could be responsible for the abnormal semen parameters. ASA generation could be a consequence of this process rather than being the cause of the abnormal semen quality. If ASA do affect fertility, this could take place in the female reproductive tract. Copyright © 1992, Wiley Blackwell. All rights reserved