The effect of blinding combined with anosmia on pituitary prolactin levels was studied in prepuberal female rats. Pituitary prolactin content and concentration were significantly depressed and the animals also evinced a noticeable retardation in the growth of their reproductive organs. Pinealectomy, when performed concurrently with blinding and olfactory bulb removal, prevented the fall in prolactin levels and ovarian weights and resulted in uterine weight levels between those of blind anosmic and untreated animals.