Twenty-nine unicondylar fractures of the distal femur were treated at the Trauma Center "Bergmannsheil", University of Bochum, Germany, between 1981 and 1994. All patients sustained their injuries from severe direct trauma. There were 16 lateral condylar fractures, 7 medial condylar fractures and 6 tangential posterior ("Hoffa-type") fractures. Twenty-eight closed injuries and 1 grade IIIB open fracture injuries to the skeleton. All fractures were treated with open reduction and internal fixation with screws within 8 h of admission. Postoperative management consisted of early continuous passive motion and minimal weight-bearing for 6-8 weeks, progressing to full weight-bearing. The mean follow-up was 68 months (18-120). The therapeutic outcome (clinical result, radiographs) was rated by the Neer score. Twenty-seven patients were available for follow-up examination. Of these, 23 were rated as excellent. 3 achieved satisfactory results, and 1 had an unsatisfactory result. All patients who did not achieve an excellent outcome had had accompanying injuries. Open reduction and internal screw fixation of unicondylar femur fractures provided overall excellent long-term results. The therapeutic outcome was significantly affected by associated injuries of the skeleton.