Two ranitidine dosages were compared for the treatment of erosive esophagitis in a multicenter, double-blind, randomized, parallel-group, placebo-controlled study. Adults with endoscopically verified erosive esophagitis were treated with either ranitidine 150 mg four times daily (n = 106), ranitidine 300 mg four times daily (n = 106), or placebo (n = 116) for up to 12 wk. Patients were also encouraged to adhere to lifestyle modifications (e.g., to elevate the head of bed, etc). Erosive esophagitis healing, determined by endoscopy, was achieved in 69% and 62% of ranitidine-treated patients by 8 wk and in 79% and 74% by 12 wk (150 mg and 300 mg, respectively) compared with 28% of placebo-treated patients by 8 wk and 40% by 12 wk (p < 0.001 ranitidine vs. placebo). Onset of heartburn relief occurred within 24 h of initiating either ranitidine dosage, and relief was maintained throughout the 12-wk study. Both ranitidine dosages displayed safety profiles similar to that of placebo. We conclude that ranitidine 150 mg or 300 mg administered four times daily is effective for healing erosive esophagitis and relieving its symptoms.