Patients undergoing human menopausal gonadotropin (hMG) superovulation were reviewed retrospectively to determine whether fecundity was greater for intrauterine insemination (IUI) than timed intercourse. Forty patients with unexplained infertility, American Fertility Society I or II endometriosis, luteal phase defect and/or cervical factor were treated with hMG alone or hMG plus IUI. Twenty-eight underwent 52 cycles of hMG/IUI, and 19 underwent 31 cycles of hMG. The probability of pregnancy after four cycles was significantly better in the hMG/IUI group (.90) than the hMG group (.37, P = .049). There was a 54.5% multiple pregnancy rate, and one patient was admitted to the hospital for hyperstimulation. When traditional therapy fails, hMG/IUI significantly increases the pregnancy rates as compared to hMG with timed intercourse in a 'good prognosis' group of patients.