We retrospectively reviewed supracondylar distal humeral fractures that had been treated with fracture-specific plating and definitive fixation through a lateral approach with a medial triceps mobilization technique. We determined the incidences of preoperative and postoperative radial nerve palsies (RNP) to evaluate the impact of the plating and fixation technique on RNP. Seventy-three patients treated at our institution from 2006 through 2009 were included in the study. The patients were assigned to 2 groups: 57 to the blunt injury group (motor vehicle collisions, falls, struck pedestrians, throwing) and 16 to the gunshot wound group. The incidence of known preoperative RNP in the blunt injury group was 27% (13 of 48 nonintubated patients); the incidence of known preoperative RNP in the gunshot wound group was 20% (2 of 10 nonintubated patients). The incidence of postoperative RNP for the combined groups of nonintubated patients who had intact radial nerve function preoperatively was 12% (5 of 43 patients). We found a high frequency of preoperative RNP, and we found postoperative RNP rates similar to those reported in the literature despite the use of the lateral approach medial triceps mobilization technique with a fracture-specific plate.