Eighteen acute humeral shaft fractures were managed with closed Kuntscher nailing. Six were pathologic fractures. Stability, pain relief, and evidence of early fracture healing were achieved. Twelve fractures were stabilized because of multiple trauma and/or inadequate closed reduction: 11 of these healed within 3 months, and only one delayed union occurred. The most frequent complication was a decreased range of motion in the shoulder, which improved with rehabilitation. Despite reports of high complication rates, we have found that intramedullary fixation of the humerus can be used in selected patients with good results.