Aim: To assess the frequency and the risk factors of stress-induced gastrointestinal (GI) bleeding in children admitted to a pediatric intensive care unit (PICU). Methods: The medical records of children aged between 1 month and 15 years admitted to the PICU between January 2002 and December 2002 were reviewed. Demographic data, indications for PICU admission, principle diagnosis, and basic laboratory investigations were recorded. Previously described factors for stress ulcer bleeding (mechanical ventilation, sepsis, acute respiratory distress syndrome, renal insufficiency, coagulopathy, thrombocytopenia, and intracranial pathology) were used as independent variables in a multivariate analysis. Results: One hundred and seventy of two hundred and five medical records were eligible for review. The most common indication for PICU admission was respiratory failure (48.8%). Twenty-five children received stress ulcer bleeding prophylaxis with ranitidine. The incidence of stress ulcer bleeding was 43.5%, in which 5.3% were clinically significant bleeding. Only mechanical ventilation and thrombocytopenia were significantly associated with stress ulcer bleeding using the univariate analysis. The odds ratio and 95% confidence intervals were 5.13 (1.86-14.12) and 2.26 (1.07-4.74), respectively. However, the logistic regression analysis showed that mechanical ventilation was the only significant risk factor with the odds ratio of 14.1. Conclusion: The incidence of gastrointestinal bleeding was high in critically ill children. Mechanical ventilation was an important risk factor for gastrointestinal bleeding. © 2005 The WJG Press and Elsevier Inc. All rights reserved.