PURPOSE Treatment of mandibular angle fractures using one or two osteosynthesis plates is still a controversial topic. Fracture, treatment, and patient-dependent influencing factors could affect the overall outcome. In the present retrospective study, complication rates of mandibular angle fractures treated by open reduction were assessed according to type of treatment. MATERIALS AND METHODS We analyzed retrospective medical records using the search terms "mandibular angle fracture." We included all patients presenting with a mandibular angle fracture treated by open reduction and internal fixation at our department between 2002 and 2012. RESULTS We included 186 patients treated with open reduction and miniplate fixation (84 one plate; 102 two plates). The early complication rate was significantly higher for the double-plate group (72.5% vs. 47.6%, respectively; p = 0.001). Most common findings in the postoperative period were transient hypoesthesia and tissue swelling. In the two-plate group, a significantly increased operation time of 183 min versus 150 min in the one-plate group was found (p < 0.001). Late complications did not differ significantly between both groups (21.4% single-plate group; 30.4% two-plate fixation group; p = 0.32). CONCLUSION We found a significantly increased early complication rate in the two-plate group. Long-term complications did not differ between both groups.