BACKGROUND: Secondary analyses from previous studies indicated that esomeprazole was more effective than lansoprazole and omeprazole in healing moderate or severe (Los Angeles grades C or D) erosive oesophagitis (EE). AIM: To compare prospectively healing rates with esomeprazole vs. lansoprazole in patients with moderate to severe EE. METHODS: In this multicentre, randomized, double-blind, parallel-group trial, adult patients with endoscopically confirmed moderate or severe EE received esomeprazole 40 mg (n = 498) or lansoprazole 30 mg (n = 501) once daily for up to 8 weeks. The primary end point was EE healing through week 8. Secondary assessments included investigator-assessed resolution of symptoms and safety and tolerability. RESULTS: Time to healing was significantly different (P = 0.007), favouring esomeprazole. Estimated healing rates at week 8 were 82.4% with esomeprazole 40 mg and 77.5% with lansoprazole 30 mg. Heartburn resolved at week 4 in 72% and 64% of patients who received esomeprazole and lansoprazole, respectively (P = 0.005). Control of other GERD symptoms was similar between treatments. Both treatments were well tolerated. CONCLUSIONS: With 8 weeks' treatment, esomeprazole 40 mg once daily heals moderate to severe EE faster and in more patients, and resolves heartburn in more patients after 4 weeks of treatment, than lansoprazole 30 mg once daily.