Expected clinical manifestations of intussusception include paroxysmal abdominal pain, vomiting, abdominal mass, and with time, rectal bleeding. We report a case where lethargy and vomiting are the presenting complaints. Diagnostic delay was encountered for this infant who had altered sensorium without accompanying pain, melena, or mass on initial examination. Either plain radiographs, supplemented by ultrasonography of the abdomen, or a barium enema should be performed in infants with unexplained lethargy.