The effects on intragastric p11 and gastrin secretion of once daily pantoprazole (40 mg) and a new formulation omeprazole (20 mg) in a Multiple Unit Pellet System (MUPS) were investigated during two treatment periods of 7 days each in a randomized crossover study with 16 healthy Helicobacter pylori-negative male volunteers. Intragastric pH was measured using continuous 24 hour pH-metry on days 1 and 7. The results were compared to the baseline curves obtained before each treatment period. On day 1, pantoprazole raised the intragastric pH significantly higher and more quickly than omeprazole MUPS (pH median 1.9 vs. 1.6, baseline pH 1.4). After 7 days, the 24 h gastric pH medians were still in favor of pantoprazole (pH 3.0 vs. 2.8). With respect to the basal gastrin concentration, both treatments resulted in similar increases. For pantoprazole, no differences were observed in AUC and Cmax after single and repeated dosing. However, the new omeprazole MUPS formulation still showed the well-known effect of initial low bioavailability increasing after repeated dosing. Pantoprazole and omeprazole were well tolerated. There seems to be no advantage in the new omeprazole formulation compared with the conventional capsule with regard to bioavailability and increase in intragastric pH. The results of this study confirm former results in which pantoprazole (40 mg) was shown to be significantly superior to omeprazole (20 mg) in elevating intragastric pH.