Different regions of the hypothalamus were electrically stimulated in anesthetized adult female turkeys. Plasma levels of prolactin (Prl) were measured before (-20, 0 min), during (5, 10, 20, 30 min), and after (5, 15, 30, 60, 90 min) a 30-min period of electrical stimulation. In turkeys with electrode placements in the regions of the preoptic-anterior hypothalamus, ventromedial hypothalamus, inferior hypothalamus, and the median eminence, the onset of stimulation increased plasma Prl within 5 min (P < 0.05) and the maximum level was reached by the end of the 30-min stimulation period. The termination of hypothalamic stimulation was followed by decreased plasma Prl to prestimulation levels. In a subsequent study plasma Prl was measured in hens at different stages of the reproductive cycle, following electrical stimulation in the ventromedial hypothalamus. Ventromedial stimulation induced increases in plasma Prl in laying, photorefractory, and incubating turkeys; however, the relative change in the maximal Prl level was greater in incubating (21-fold) than in either laying (3.5-fold) or photorefractory (5-fold) turkeys. We conclude that Prl release in the female turkey can be affected by electrical stimulation of selected hypothalamic areas and that stimulation-induced Prl release in the ventromedial hypothalamus is enhanced in incubating turkeys.