Previous works have documented that pentagastrin has a stimulatory effect on salivary secretion. In this paper, we have studied the action of caerulein, a peptide that has an active gastrin-like terminal tetrapeptide, on salivary secretion in man. Our data documented that caerulein and pentagastrin have a similar excitatory effect on gastric secretion in man, but different actions on salivary flow. Caerulein, at increasing doses, inhibits salivary flow, but not the secretion of amylase; this effect is statistically significant at 0.5 µg/kg/h which is the same dose that maximally stimulates gastric secretion. The inhibitory effect of caerulein was not reversed by previous injection of papavarin