The effect of vasoactive intestinal peptide (VIP) and peptide histidine isoleucine (PHI-27), peptides of the glucagon-secretion family, on oxytocm release were examined in a perifusion system by perifusing the hypothalamo-pituitary complex from normal female rats in diestrus. VIP at 10^, M had no significant effect on oxytocin release from the hypothalamo-pituitary complex. Medium containing 10^M PHI also induced no significant release of oxytocin. These date indicate that VIP and PHI in a dose range which stimulates prolactin secretion have no effect on oxytocin release in vitro.