One hundred five consecutive patients with a diagnosis of delayed union (61 patients) or nonunion (44 patients) of the femoral shaft from February 1968 to November 1983 were managed by intramedullary reaming and nailing. The procedure was accomplished by closed techniques in 82 of the cases. Adequate follow-up study was obtained in 101 patients; all but four showed clinical and radiologic union at an average of 20 weeks following the procedure, with an overall union rate of 96%. The four patients whose fractures failed to consolidate with this treatment had repeat procedures with placement of thicker nails, and all subsequently healed.