The effects of cisapride, a nondopaminolytic motility-enhancing agent, were studied in 56 patients with chronic functional dyspepsia; all had symptoms suggestive of delayed gastric emptying. The patients received 4 mg or 8 mg of cisapride or placebo orally three times daily for two successive three-week periods according to a randomized, double-blind, crossover study design. Although there was a high placebo response (55% showed good or excellent results), the global response to treatment was significantly (P = 0.024) in favor of cisapride (75% had good or excellent results). The drug was particularly superior to placebo (P = 0.03) in the improvement of a cluster of symptoms typical of postprandial discomfort, including early satiety and nausea. Side effects were minimal.