Ejaculatory patterns were observed in normally reared, postpuberally castrated male and female rats treated with sex hormones and electrical shock in adulthood. In a preliminary experiment, 3 females treated with 50 microgram estradiol benzoate (EB) and 500 microgram progesterone (P) showed intromission and ejaculatory behavior when subjected to shock. Refractory periods were abnormally short and there was almost no postejaculatory vocalization. In Experiment 1, males and females were tested with electrical shock following daily treatment with 32 microgram EB with and without 500 microgram P on the test day. There was no difference between males and females in preejaculatory behavior, but females displayed abbreviated refractory periods and no postejaculatory vocalization. Progesterone had no observed effect. In Experiment 2 castrated males and females were subjected to shock after treatment with 8 microgram EB per day for 3 weeks. No P was given. Again females showed drastically reduced refractory periods and little vocalization. In Experiment 3, males and females treated with TP and shock displayed ejaculatory patterns, normal refractory periods and vocalization. Results show that female rats are capable of exhibiting the ejaculatory response without sex hormone treatment in perinatal life or androgen treatment in adulthood. It was also demonstrated that there is a sex difference in the postejaculatory behavior shown by estrogen-treated male and female rats.