Morphological and morphometric assays showed that administration of antibodies to the prostate-specific antigen in ultralow doses for 1.5 months delayed the development of atrophic and sclerotic processes in rats with chronic aseptic prostatitis. The concentration of zinc ions playing an important role in binding of androgens increased in the prostate of rats receiving the preparation. Studies of copulatory behavior showed that male rats with chronic prostatitis receiving antibodies to the prostate-specific antigen displayed increased sexual activity compared to control and intact animals.