Open reduction and internal fixation (ORIF), the currently preferred method for treatment of unstable posterior pelvic and sacral fractures, has two significant disadvantages: the need for blind placement of the fixation screws and the occurrence of high complication rates. Advantages of computed tomographic (CT)-guided sacral fixation include direct visualization of the course of the screws and absence of significant complications. Eight patients with unstable but reducible sacral fractures or sacroiliac joint (SIJ) disruptions (seven unilateral and one bilateral) underwent CT-guided sacral fixation with use of the standard orthopedic A-O, 7.0-mm-diameter cannulated screw system. The guide pin was positioned across the fracture or SIJ by using depth and angulation measurements derived from the scout CT scans. After confirmation of the position of the pin with CT, the screw tract was drilled, and the cannulated screw was placed into position. Radiographic and clinical follow-up (5-9 months) showed healing with no significant complications in all eight patients. CT-guided sacral fixation is a safe alternative to ORIF in patients with reducible unstable pelvic fractures.