Normal fetal and newborn prostates were studied to evaluate growth patterns, histogenesis, and secretory activity. Whole cross-sectioned prostates harvested from 107 necropsies of fetuses and newborns ages 20 weeks gestation to 1 month of age were used. Development of the prostate occurred in three stages: bud stage (20-30 weeks gestation), bud-tubule stage (31-36 weeks gestation), and acinotubular stage (37-42 weeks gestation). Squamous metaplasia often appeared in the urethra, utricle, and primary lobular ducts, and occasional microcysts were noted. PAS and alcian blue-PAS positive secretion were present in 65% of the specimens by 20-30 weeks gestation and in over 87% of the specimens by 37 or more weeks gestation. Secretory activity was most prominent in the lateral regions of the peripheral zone. Prostate-specific antigen was only weakly detected throughout the prenatal period and was not related to secretory activity as evidenced by the PAS technique.