A fracture-separation of the distal humeral epiphysis in children is an extremely rare injury and presents problems in diagnosis, radiographic interpretation and management. From June 1992 to December 1996, Authors experienced the 5 cases of Salter - Harris type II injury of the distal humeral epiphysis at Department of Orthopedic Surgery, Pusan Maryknoll General Hospital. The patient were followed up from one year nine months to three years four months. The two cases were treated by closed reduction and percutaneous K-wire fixation and the three cases by open reduction and internal fixation with K-wires. There were 4 cases of complication seldom reported following fracture-separation of the distal humeral epiphysis. This complications consist of 4 dissolutions of trochlea, which is one, frank avascular necrosis of trochlea. In 3 cases with open reduction developed the cubitus varus & dissolution of trochlea. We speculate that this complications results from avascular necrosis of distal end of humerus. Attention to change of carrying angle and radiographic change of distal humeral end are important in detection of complication & evaluation of etiology of dissolution of distal humeral end.