To evaluate the therapeutic potential of the newly developed proton pump inhibitor lansoprazole in patients with reflux esophagitis (grade I and II according to Savary Müller criteria), the authors performed a single blind, randomized clinical trial comparing 20 mg omeprazole and 30 mg lansoprazole, involving 60 patients at two clinical hospitals. The treatment period was or 8 weeks, and main efficacy variables were healing of endoscopic changes and relief of reflux symptoms. No significant difference in terms of healing and relief of reflux symptoms was found either after 4 or after 8 weeks of treatment. In conclusion, 30 mg lansoprazole daily was found to be safe and effective therapy comparable to omeprazole in the short-term treatment for reflux esophagitis (grade I and II).