We treated 16 delayed unions and 57 nonunions of the tibial diaphysis with a below-the-knee functional brace. In 48 cases, bracing was preceded by fibular ostectomy, and ten patients had an additional bone graft. We were able to follow 67 patients, of whom six (8.7%) failed to respond to treatment. In patients with nonunion, bony healing occurred with a median of 4 months. There was no difference in the speed of healing according to the level of the defect. Shortening of the limb following ostectomy of the fibula had a mean of 3 mm in the delayed-union group and 5 mm in the nonunion group.