Critically ill patients are at risk for development of stress-related mucosal damage (SRMD). Proton Pump Inhibiros (PPIs) like pantoprazole are extensively used to prevent SRMD in ICU settings. It is not known with certainty that either oral or intravenous pantoprazole is associated with a better response. Our goal was to compare effects of intravenous pantoprazole with oral pantoprazole on gastric pH in children admitted to PICU. In this blinded trial, 80 patients were randomly divided into two groups. Patients in in the first group received oral pantoprazole (1 mg/kg/day/divided) and patients in the second received IV pantoprazole (1 mg/kg/day/divided). The gastric pH was measured 48 hours after pantoprazole administration using litmus paper. The mean age was 990 days. After 48 hours, the gastric pH was 4.46 ± 1.48 in patients received pantoprazole orally and it was 4.85 ± 1.52 in patients received pantoprazole intravenously. There was no significant difference between two study groups (P= 0.252). Besides, no significant differences were noted in rate of diarrhea and nosocomial pneumonia between 2 study groups (P > 0.05). This study showed that both intravenous and oral pantoprazole had similar effects on gastric acid of children hospitalized in PICU. It seems reasonable to use oral pantoprazole to reduce the costs of treatment. Manuscript profile