To study the effects of late open reduction of lateral condyle fracture (LCF) on avascular necrosis (AVN), amount of displacement, and improvement, the records of 11 children with an open capitellar physis and a malunion or a nonunion treated >3 weeks after injury were reviewed. Preoperative and postoperative displacement amounts were recorded. Radiographs were reviewed for AVN, lateral overgrowth, or fishtail deformity. There were no cases of AVN. Three patients had occasional pain. Four patients had displacement of >10 mm before surgery. In fractures with >1 cm of displacement, fragment position was minimally improved surgically, but final alignment and range of motion were good. These fractures showed more radiographic deformities at the time of late open reduction. The risk of AVN with late open reduction of LCF at >3 weeks is reduced if no tissue is stripped off the fracture fragment posteriorly. Even children without anatomic reduction had functional arms with little or no pain.