Fracture-separation of the distal humeral epiphysis is a rare injury, frequently misdiagnosed as a fracture of the lateral humeral condyle, a supracondylar fracture of the humerus or a dislocation of the elbow. Roentgenographic evaluation reveals posteromedial displacement of the distal epiphysis. Single contrast arthrography is performed in order to confirm diagnosis. Treatment is first directed toward prompt recognition of the injury. A manipulative closed reduction is usually recommended. We experienced a case of fracture-separation involving the entire distal humeral physis treated by closed reduction and percutaneous pinning. The result was excellent.