Beneficial effects of zinc therapy in some infertile patients with low seminal zinc concentrations and decreased sperm motility have been reported recently. The effects of zinc therapy, low-dose (5-10 mg/day) androgen therapy, and combination therapy of both zinc and low-dose androgen, on sperm motility and seminal zinc concentration were studied in patients referred to the andrology clinic. Low-dose androgen therapy increased seminal zinc concentrations and sperm motility, only when pretreatment seminal zinc concentrations were low. Furthermore, patients with low seminal zinc concentrations and poor sperm motility showed greater improvement of sperm motility and seminal zinc levels in response to zinc sulfate with fluoxymesterone than did fluoxymesterone alone or zinc sulfate alone, possible due to a synergistic effect of zinc and androgen.