Dental implant systems using computer-aided surgical guide have advantages over the conventional procedures. A retrospective observational study was carried out to 56 dental implants placed according to surgical guide developed by CAD/CAM system. The guide included toothsupported, and mucosa-supported surgical guide and implant placement in all areas of the jaws. The virtual planning was superimposed on a tomography to evaluate the precision parameters including platform distance, apex distance, angular deviation, and depth of implants. Objectives to determine the accuracy of CAD/CAM system with a computer-aided surgery for dental implant placement based on the design and placement site. Regarding the precision parameters, the platform distance was at 1.38 mm (± 0.66), the apex distance at 1.63 mm (± 0.97), the angular deviation at 3.97º (± 3. 34º) for, and the depth of implants at 1.11 mm (± 0.97). 0.72). The precision parameters had no significant difference on the implant placement in the jaws, but there was a significant difference on the platform distance (p = 0.0096) according to the guide. It has been found that the tooth-supported surgical guide had the best precision. The precision of implant placement using computer-assisted surgical guides with the CAD/CAM system was maintained according to the antecedent precisión parameters. The guide design is a considerable factor for producing better precision as expected tooth-borne.