BACKGROUND Gastro-oesophageal reflux disease, a term used to refer to chest symptoms that result from reflux of gastric acid into the oesophagus, occur at least daily in 7% and every 3 days in 33% of the population. METHODS One hundred and forty-one patients with moderate to severe gastro-oesophageal reflux symptoms occurring at least three times per week (but no oesophageal erosions or ulcers at endoscopy) were treated in this randomized, double-blind, placebo-controlled study at six trial centres. Treatment was given for 6 weeks and consisted of daily doses of either 1 g sucralfate gel b.d. or placebo. The evaluation of efficacy was based on data of 139 patients. RESULTS The responder rate at Day 42 was statistically significantly higher for the patients treated with sucralfate (71%) than for the placebo patients (29%) (P < 0.0001, Fisher's exact test). The overall response of the non-ulcer dyspepsia and gastro-oesophageal reflux disease symptoms was better for sucralfate gel than for placebo with 45% of patients treated with sucralfate gel being considered as having a 'good' or 'excellent' overall response compared with 22% of the patients who received placebo (P < 0.0001, Wilcoxon test). Only a few adverse experiences were reported by 10% of sucralfate patients and 7% of placebo patients. CONCLUSIONS In this trial, we demonstrated a statistically significant superiority of sucralfate gel at a dosage of 1 g b.d. compared to placebo in the treatment of patients with gastro-oesophageal reflux disease. Sucralfate gel was well tolerated.