Gastrointestinal stromal tumor is a rare pathology in childhood. It may occur anywhere along the alimentary tract and represents with a wide spectrum of signs and symptoms according to location. An infant with malignant colonic stromal tumor that has presented with a huge abdominal mass and lower gastrointestinal bleeding is reported to discuss the difficulties in diagnosis and differential diagnosis of this unusual tumor. Copyright 2003, Elsevier Science (USA). All rights reserved.