PURPOSE: The purpose of this study is to report on the use of a computer-assisted design (CAD) system for predictable preoperative planning of orbital implant surgery (determination of the optimal number and position of orbital implants). MATERIALS AND METHODS: Preoperative computed tomographic data were processed by interactive software for predictable surgical planning of orbital implant placement. Reformatted images from axial scans were used to analyze the structure of orbital bone and to plan the number of implants to place and the sites in which to place them. RESULTS: Surgeries to correct orbital defects in 6 patients were successfully designed with this method. Seventeen implants were placed in 6 patients with the CAD system with no intraoperative injuries. Satisfactory anatomic and esthetic results were achieved. CONCLUSIONS: The new CAD system optimized preoperative surgical planning for orbital implant placement. The software may be applied in other craniofacial areas for implant placement in the future.