Statement of Problem: Dilaceration is defined as a sudden change in the axial inclination of root or between the crown and the root of a tooth. There is no previous study evaluating its prevalence in south of Iran.Purpose: This study evaluates the prevalence of root dilaceration on the basis of its location in dental arch in a sample of dental patients referring to Shiraz dental school, Iran.Materials and Method: This retrospective study was performed using full mouth periapical radiographs of 250 patients who were referred to Shiraz dental school. Buccal and lingual dilaceration was determined by its known” bull’s eye” appearance in the radiographs or if the deviation was in the mesial or distal directions; the angle of 90 degree or greater between the deviation and the axis of root was the inclusion criteria.Results: Root dilaceration was detected in 0.3% of teeth and 7.2% of patients. It was distributed equally between the maxilla and mandible. Mandibular second molar was the most frequent dilacerated tooth (1.6%) followed by maxillary first molar (1.3%) and mandibular first molar (0.6%). The alveolar nerve was the most common anatomic structure near dilacerated teeth.Conclusion: According to this study, root dilaceration is an uncommon developmental anomaly which occurs mostly in the posterior teeth.