In an effort to evaluate the effect of hCG/human menopausal gonadotropin (hMG) treatment on semen parameters in normogonadotropic men suffering from oligospermia, a double blind, placebo-controlled study was conducted. After 2 basal examinations of seminal parameters and reproductive hormones, 39 men were recruited for the trial. Nineteen men, allocated randomly to the active drug group, received im injections of 2500 IU hCG twice a week in combination with 150 IU hMG three times a week for 13 weeks, while 20 men were treated, following the same injection schedule, with NaCl only. After the 13-week treatment period, follow-up examination was performed, followed by 3 additional examinations at 4-week intervals. Of those men receiving hCG-hMG, 2 induced pregnancies in their wives, while no pregnancies were reported in the placebo group. Sperm concentrations, the percentages of motile sperm, and the proportions of normally formed spermatozoa, however, were similar in the 2 groups at all times. It was not possible to predict the outcome of treatment based on results of GnRH and hCG tests performed before the treatment phase.