A combined anterior and posterior approach was used for the resection of a large tumor (a chordoma, a giant-cell tumor, an osteosarcoma, or a chondrosarcoma) of the cephalad part of the sacrum in twelve patients. The anterior aspect of the sacrum was exposed through an extended ilioinguinal approach, and the posterior aspect, through a midline approach. This widely extensile procedure permitted simultaneous visualization of the anterior, posterior, and circumferential aspects of the sacrum at the time of the osteotomy and facilitated the resection of these difficult lesions. At the time of follow-up (average duration for the eleven surviving patients, thirty-seven months; median, thirty months; range, twenty to sixty-nine months), ten patients were able to walk independently (four with the use of a cane) and one was confined to a wheelchair. One patient had died immediately postoperatively. The results of the present study indicate that a combined extended ilioinguinal and posterior approach can be used effectively for the wide resection of a tumor arising in the cephalad part of the sacrum.