One hundred and sixty femoral shaft fractures (in 154 patients) all treated in the same hospital, seventy-seven by early Kuntscher nailing and eighty three by traction and a spica cast, were studied retrospectively and the costs of treatment were analyzed and projected for the future. Twenty-nine per cent of the patients treated by traction and a cast had complications all requiring surgical treatment, mostly by secondary nailing. Including primary and secondary nailings, there were nineteen complications after 100 nailings. Of these complications, three were major infections and four were fracture healing problems. The healing time was less in the closed group, but the time in the hospital and time to return to work were less in the nailed group. The cost of care both now and projected was 20 to 30 per cent less for open reduction and nailing. It was concluded that open treatment has decided advantages despite the risks of infection.