Antegrade intramedullary nailing and bone grafting was carried out for 27 patients with resistant atrophic nonunion of the humeral diaphysis. The initial fracture was open in 12 cases and closed in 15. There were ten proximal humeral fractures, 13 mid-shaft fractures and four distal humeral shaft fractures. Most had previous attempts at internal fixation with bone grafting. Fifteen cases united, but 12 remained ununited necessitating further surgical treatment. The failures were all in the more complex cases. Lack of rigidity and compression may be the problem.