Extended approaches are indicated for complex acetabular fractures. The advantage of extended approaches is the simultaneous exposure of both columns of the acetabulum; disadvantages are the wide exposure of the soft tissue and a high rate of heterotopic ossification. Muscle weakness and necrosis of the muscle have been described. Although there is good exposure with an extended approach, the indication for it is restricted. Between 1972 and 1993, 688 patients with acetabular fractures were treated at the Trauma Department of the Hannover Medical School; 322 had open reduction and internal fixation. Thirty-five patients (10%) were treated with an extended approach. In a retrospective study of 24 patients treated with an extended approach between 1985 and 1993, perioperative data, long-term clinical outcome and radiological outcome were investigated. The aim of the study was to compare the outcome of two groups treated using either the classical extended iliofemoral approach or the Maryland modification. Eleven patients were treated with the extended iliofemoral approach, 13 with the Maryland approach. There were no significant differences in age, type of accident, fracture classification, time to operation, time of operation and blood loss. The postoperative X-ray was anatomic or nearly anatomic in 22 cases; 2 patients had a dislocation of more than 2 mm. The main complications were hematomas and seromas. In both groups we found one thrombosis and one nerve injury with partial recovery. Twenty patients were followed up at least 2 years after trauma, 8 after extended iliofemoral approach and 12 after Maryland approach. There was no correlation between clinical and radiological outcome. In the clinical outcome (Merle d'Aubigne-Score) there were no excellent results. Six patients with Maryland approach had an excellent radiological result versus one after extended iliofemoral approach. Six patients had poor clinical results, three after each approach; one patient developed acetabular head necrosis, subsequently treated with THR, after the Maryland approach, two had severe coxarthrosis after the extended iliofemoral approach and the others had severe pain or functional impairments. Significant heterotopic ossification (Brooker type III) developed in three cases, one after the Maryland and two after the classic approach. There were no significant differences between these two approaches. The indication for an extended approach should be restricted in the case of complicated fractures. Where it is indicated at all, the Maryland modification seems to be technically advantageous.