In a study evaluating the efficacy and safety of lansoprazole to prevent the relapse of erosive esophagitis (EE), 206 of 241 patients (85%) healed after open-label treatment with lansoprazole 30 mg once daily for 8 weeks and received double-blind maintenance treatment with lansoprazole 15 mg once daily or ranitidine 150 mg twice daily for up to 1 year. At 1 year, 67% of lansoprazole-treated and 13% of ranitidine-treated patients remained healed (P<0.001). Lansoprazole-treated patients experienced significantly greater symptom relief (P<0.001), and, if asymptomatic at entry into the maintenance phase, remained asymptomatic for significantly longer than ranitidine-treated patients (P<0.001). Symptom status correlated with healing (P=0.001), supporting the symptom-directed management of EE. Both treatments were well tolerated and no unexpected events occurred. Daily therapy with lansoprazole to prevent the relapse of EE is effective, well tolerated, and superior to ranitidine in the maintenance of healing and symptom relief.