In a double-blind, placebo-controlled, randomized study we measured the effect of 1 mg/kg intravenous metoclopramide on the gastric emptying of a 15 ml/kg 5% glucose meal, using a phenol red dye dilution technique. In a group of nine infants referred for multiple daily episodes of regurgitation, metoclopramide doubled the rate of gastric emptying (p less than 0.02). In six infants with prolonged gastroparesis following abdominal surgery, metoclopramide more than doubled the rate of gastric emptying (p less than 0.05). In contrast, in seven infants with gastroparesis related to prematurity, metoclopramide did not significantly change gastric emptying. No extrapyramidal side effects of metoclopramide occurred during the study.