Background/Aims : We prospectively compared the efficacy and safety of the two products of omeprazole based triple therapy in patients with Helicobacter pylori (H. pylori)-positive active peptic ulcer. Methods : Seventy-four patients with endoscopically proven active peptic ulcer were divided into two groups: OAC-I group (n=37) which received the 6-weeks treatment of A product of omeprazole (20 mg, b.i.d.) plus 2 weeks treatment of amoxicillin (500 mg, b.i.d.) and clarithromycin (500 mg, b.i.d.); OAC-Ⅱ group (n=37) which received 6 weeks treatment of B product of omeprazole (20 mg, b.i.d.) plus 2 weeks treatment of the same antibiotics. The H. pylori and ulcer healing status were assessed at baseline and at the end of the 6-week therapy. Gastrointestnal symptoms, adverse events were checked and the standard laboratory examination was performed at each visit. Results : Eradication of H. pylori [intention to treat (n=77)/per protocol (n=66)] and healing rate of ulcer were 83.8%/ 96.9% and 93.8% in OAC-I group, 91.9%/100% and 97.1% in OAC-II group (P=0.477, P=0.608). No significant differences were found in symptom resolution, adverse events, and laboratory monitoring between the two groups. Conclusions : The two different products of omeprazole based triple therapy for ulcer showed similar healing rates and safety after 6-weeks treatment in patients with H. pylori-positive active peptic ulcer. (Kor J Gastroenterol 2000;36:29 - 38)