The aim of the present study was to evaluate the long-term outcome of immediately loaded full-arch, fixed, one-piece prostheses supported by dental implants inserted in completely edentulous maxillae and mandibles. Twenty-eight completely edentulous jaws in 27 patients were treated with screw-fixed provisional prostheses on the same day as implant insertion. A total of 189 implants were inserted into the jaws of the patients. All provisional prostheses were the one-piece bridge type and were made with acrylic resin. Final restoration was performed more than 2 months after surgery. Implant survival rate, prosthesis success rate, and complications during the follow-up period were evaluated. Implant size (diameter and length) and bone quality (Hounsfield units) of the region of the implant were also analyzed. Mean follow-up time was 77.9 months. The cumulative survival rate of the implants was 100%, and the success rate of the prostheses was also 100% during the observation time. Although 3 types of minor complications occurred in 10 jaws (10/28; 35.7%), no major complications were found. Immediate loading of dental implants produces an equivalent outcome as that reported in previous studies using conventional loading. We believe this study not only adds to the immediate loading data but also confirms that the immediate loading technique may be most advantageous strategy for edentulous patients.