Pudendal nerve palsy after femoral intramedullary (IM) nailing was retrospectively reviewed in 65 nailings performed on 63 patients. Ten pudendal nerve palsies (15%) were noted in eight male patients and two female patients. Three male patients had autonomic involvement affecting erections. All palsies were transient (3-173 days), and occurred in patients done in the supine position as opposed to the lateral position. A possible etiology is the smaller perineal post used in the supine position that may penetrate the pelvis deeper, compressing the pudendal nerve. Other factors may be operating time and amount of traction. As prevention, the perineal post must always be adequately padded, and the operating time and amount of traction should be minimized to decrease the incidence of pudendal nerve palsy. Because pudendal nerve palsy appears to be a common complication in femoral IM nailing, the patient must be informed of this possibility.