A hemophiliac with a self-inflicted abdominal stab wound was evaluated with computerized tomography, ultrasound, and technetium-99m labeled red blood cell (Tc-99m RBC) imaging. A large intra-abdominal hematoma was best defined by CT and ultrasound; however, continued bleeding, indicating the need for emergency surgery, could only be demonstrated by radiolabeled red blood cell scintigraphy.