Forty-two cases of fracture of the humerus associated with paralysis of the radial nerve and treated over a period of 30 years were analysed. There was predilection for the mid-distal third, followed by the mid third and the supracondylar segment. Paralysis was complete in 39 cases and partial in 3. Treatment was conservative in 14 cases, early surgical in 18 (within 30 days), and late surgical in 10 (mean 4.7 months). The latter group involved cases where conservative treatment had not achieved recovery of neural function. Of the fractures treated conservatively, the diaphyseal fractures were slightly or moderately displaced, while supracondylar fractures were very displaced. Most of the fractures treated surgically were moderately or considerably displaced. Neurological recovery was satisfactory in 86% of the cases treated conservatively, in all those operated early, and in 50% of those operated late. The choice of treatment as between conservative or surgical must be on an individual basis, depending on the site and degree of displacement of the fracture, the extent of any exposure, and the degree of neurological deficit.