The effect of a prokinetic agent, cisapride, on the relapse of reflux esophagitis was investigated in a randomized, double-blind trial conducted in 443 patients whose esophagitis had previously been healed with an acid antisecretory drug. Patients received cisapride, 20 mg at night, cisapride 10 mg twice daily, or placebo for 12 months or until endoscopic relapse was confirmed endoscopically. In 88% of all patients (respectively 133, 132, and 124), endoscopic data were available at discontinuation of treatment. In comparison with placebo, the two cisapride regimens prolonged both the time to endoscopically confirmed relapse (Kaplan-Meier analysis; P = 0.001) and the time to symptomatic relapse (P = 0.012). The life-table endoscopic relapse rates at 12 months were 51% for placebo, 32% for cisapride 20 mg at night (P = 0.005), and 34% for cisapride 10 mg twice daily (P = 0.02). Patients with more severe esophagitis before healing relapsed more rapidly during maintenance therapy, regardless of the treatment regimen. Adverse events were infrequent in all three groups. These findings indicate that maintenance treatment with the prokinetic drug cisapride prevents the relapse of esophagitis after it has been healed by acid antisecretory therapy.