AIM: To compare the effect of intravenous and oral omeprazole in patients with bleeding peptic ulcers without high-risk stigmata.METHODS: This randomized study included 211 patients [112 receiving iv omeprazole protocol (Group 1),99 receiving po omeprazole 40 mg every 12 h (Group 2)] with a mean age of 52.7. In 144 patients the ulcers showed a clean base, and in 46 the ulcers showed fiat spots and in 21 old adherent clots. The endpoints were re-bleeding, surgery, hospital stay, blood transfusion and death. After discharge, re-bleeding and death were reevaluated within 30 d.RESULTS: The study groups were similar with respect to baseline characteristics. Re-bleeding was recorded in 5 patients of Group 1 and in 4 patients of Group 2 (P = 0.879). Three patients in Group 1 and 2 in Group 2 underwent surgery (P = 0.773). The mean length of hospital stay was 4.6 ± 1.6 d in Group 1 vs 4.5 ± 2.6 d in Group 2 (P = 0.710); the mean amounts of blood transfusion were 1.9 ± 1.1 units in Group 1 vs 2.1 ± 1.7 units in Group 2 (P = 0.350). Four patients, two in each group died (P = 0.981). After discharge, a new bleeding occurred in 2 patients of Group 1 and in 1 patient of Group 2, and one patient from Group 1 died.CONCLUSION: We demonstrate that the effect of oral omeprazole is as effective as intravenous therapy in terms of re-bleeding, surgery, transfusion requirements,hospitalization and mortality in patients with bleeding ulcers with low risk stigmata. These patients can be treated effectively with oral omeprazole.