Current surgical planning methods are usually not adequate for the treatment of patients with complex craniomaxillofacial (CMF) deformities. To this end, we have developed a 3-dimensional (3D) computer-aided surgical simulation (CASS) planning method for the treatment of patients with complex CMF deformities. The purpose of this pilot study was to evaluate the accuracy of this technique in the treatment of patients with complex CMF deformities.