A malunion as a complication of distal humerus fractures has been frequently linked with aesthetic problems but less frequently with posterolateral rotatory instability. We report 2 cases of childhood posttraumatic cubitus varus with subsequent posterolateral rotatory instability and their treatment with a minimum of 2 years of follow-up. The etiology of the so-called posterolateral rotatory instability of the elbow is mostly traumatic, but iatrogenic causes have also been described such as the treatment of tennis elbow and less frequently and chronically due to overuse and overload because of distal humerus malunion.