Our purpose was to examine gastric lipase secretion after cephalic stimulation (sham feeding) and to examine the effect of cholinergic blockade. Eight healthy volunteers, four women and four men, age 21-58 years, were studied twice on separate days. They were sham fed with and without infusion of atropine. Gastric content was measured and the amount as well as the activity of gastric lipase output were determined. Plasma concentrations of gastrin, secretin, and cholecystokinin (CCK) were measured simultaneously by radioimmunoassays. Cephalic stimuli can evoke human gastric lipase secretion, and this effect was almost ablated by atropine blockade of cholinergic receptors. The concentrations of CCK and secretin in plasma were unaffected by sham feeding with or without atropine blockade, whereas gastrin was stimulated by sham feeding after atropine blockade. Gastric lipase secretion in man is apparently controlled by interacting vagal and hormonal mechanisms.