Thirty normogonadotropic oligospermic males were administered Tamoxifen (20 mg/day) for 4 months. A complete evaluation of seminal parameters before and after treatment was performed. An increase of both mean sperm concentration and total sperm count was noted after treatment with Tamoxifen (p less than 0.05), whereas no variation was observed for semen volume, sperm morphologic characteristics, or sperm motility. Hormonal patterns of 5 of these subjects before, during, and after 3 months of treatment with Tamoxifen showed a progressive increase of gonadotropin (especially LH) and 17 beta E2 values; testosterone variations were minimal, and PRL showed a slight decrease.