Five double-blind trials were identified including 848 patients. The mean 4-week healing rate in patients treated with lansoprazole was 85%, which was significantly higher than the healing rate in patients treated with H2-receptor blockers (75%). This difference of 10% was significant (P < 0.01) according to the Der Simonian method, and the corresponding odds ratio of 2.27 (95% confidence interval 1.5-3.2) was significant according to the Peto method (P < 0.01). There was also a significant difference in favour of lansoprazole for 2-week healing rates (mean difference 20%, P < 0.01) and for the percentage of patients without pain at 2 weeks (mean difference 8%; P < 0.02). Indirect comparisons of 4-week healing rates showed no difference between 30 mg lansoprazole and 20 mg omeprazole and confirmed that both drugs had a greater efficacy than ranitidine, famotidine, nizitidine, cimetidine or sucralfate.