This article describes the technique of iliosacral screw fixation, as well as a retrospective review of 28 consecutive patients who had spine fusion to the sacrum with iliosacral screws, with a minimum follow-up of 2 years. The study included 6 male and 22 female patients. Average age at the time of surgery was 43 years, and mean follow-up time was 3.5 years. There were no neurologic complications at final follow-up evaluation. Ninety-five percent of the patients had radiographic evidence of fusion. Three patients required iliosacral screw removal because of suboptimal intraoperative Kirschner-wire placement. Optimal intraoperative radiographic evaluation for accurate iliosacral screw placement is recommended. The use of iliosacral screws is also a useful addition to the armamentarium of the spine surgeon when fixation to the sacrum is required.