In a ten-year study of the healing responses of thirty-one children with fresh fractures of the lateral condyle of the humerus with less than four millimeters of displacement, there were three patterns of healing. Forty-nine per cent healed rapidly in six weeks with abundant callus and periosteal new bone. Thirty-eight per cent healed slowly over eight to twelve weeks, mostly by endosteal union with little callus. Thirteen per cent had progressive displacement of the fragment in the plaster cast and required surgery to prevent non-union. Those fractures that healed had two millimeters or less of displacement of the fragment initially. Those that did not heal had an average of three millimeters of initial displacement. Established non-unions in good position that were symptomatic while the elbow was still immature were salvaged by bone-grafting, sparing the physis of the condylar fragment. The fragment united and grew with the elbow to maturity, producing an excellent end result on long-term follow-up. When the physeal plate of the ununited condylar fragment was absent, the fragment could not grow with the elbow and the result of surgery was less satisfactory.