The effect of gonadectomy, sham-gonadectomy, pinealectomy, and sham-pinealectomy on the concentration of NaCl in the total volume of fluid drunk per day ([NaCl]) in male rats offered a free choice between water and 3% saline was measured. Neonatal gonadectomy increased [NaCl] I in adult males but had no effect on immature rats. If the rats, however, were neonatally pinealectomized as well as gonadectomized, the increase of [NaCl] I also appeared in the immatures. Neonatal sham-pinealectomy decreased [NaCl] I in immature and adult rats, both gonadectomized and sham-gonadectomized. In adult neonatally gonadectomized males the effects of sham-pinealectomy did not occur in those animals actually pinealectomized. The role of the pineal gland in the regulation of water and salt intake is discussed in relation to the function of hypothalamus, neonatal stress, and sexual maturation.