The effects of testosterone, dihydrotestosterone, and otherandrogens upon gonadotropin secretion were studied using isolated female rat pituitaries maintained for 5 days. FSH and luteinizing hormone (LH) were measured by radioimmunoassay. When mean FSH release and mean final tissue content of FSH were compared in preparations containing testosterone or dihydrotestosterone (5 ng/ml) in the presence of 4 × 10<sup>–4</sup> M dibutyryl cyclic AMP (vs dbcAMP alone), both release and tissue content were significantly increased. Dihydrotestosterone, but not testosterone, significantly reduced LH release. Similiarly, in experiments utilizing LH-releasing hormone (LRH, 1.5 ng/ml), a significant increase in FSH release (128% of control values during the final 3 days of culture) and a significant increase in tissue content (152% of control values) were obtained in the presence of testosterone. Thus, testosterone in the presence of LRH did not inhibit gonadotropin release; rather, the secretion of FSH seemed to be stimulated.