Our clinical catamnestic studies on cases of sterility with a proven sensitization against spermatozoa revealed a statistically significant decrease of pregnancies only in patients with positive spermantibody tests over a period longer than 3 years. A direct spermimunological etiology of sterility can not yet be derived. In the investigated 759 cases a sensitization against spermatozoa was detected in 93 cases. In 11 patients the spermantibodies proved to be positive longer than 3 years. Washed spermatozoa were used as antigen in the applied test methods. It may very well be possible, that the results point in a different direction once we are applying a particular fertility diminishing spermatozoa antigen.