Aim: The aim of this study was to evaluate clinical features that might be related to success rates of autotransplantation of molars with complete root formation. Materials and methods: A group of 60 patients with completely formed third molars autotransplanted to a different molar socket was followed for a medium period of 5 years and 5 months. Extreme care was used in order to preserve the vitality of the periodontal ligament cells. The same technique was applied for all teeth despite different anatomies. Descriptive statistics was performed. The association of the various factors with failures was assessed by using the Fisher's exact test and a p-value of 0.05 was considered as significance threshold. Results: Autotransplantation was found to be a reliable method to replace extracted molar teeth with closed apices. The two major factors that positively influenced the outcomes were fixation with splint and a periodontal probing pocket depth less than 4 mm after the initial healing period. The technique resulted in a suitable well-conserved socket and donor tooth, after the extraction. Conclusion: An accurate case evaluation was critically important in order to identify the risks prior to surgery and to select the right patients for this procedure. Autotransplantation of third molar teeth is a feasible approach to replace compromised mature molars. Proper stabilization of the transplanted tooth is strategical for the success of this procedure. A conservative approach to unerupted wisdom teeth is also recommended. Clinical significance: Dental implants and fixed prostheses have been utilized to replace missing teeth, and orthodontic space closure can be sometimes an effective treatment option. Tooth autotransplantation can be a reliable and less invasive clinical alternative when an appropriate donor site is available.