Introduction: The use of panoramic radiography has shown a remarkable expansion over the past 20 years. Accurate positioning and preparation of patients is needed to avoid image distortion. The aim of this study was to evaluate the common errors on panoramic radiographs taken in the radiology department of Rasht dental school. Materials and Methods: The study sample included 390 digital panoramic radiographs taken in Rasht faculty of dentistry by a direct digital panoramic unit. Frequency of common errors including errors related to patient positioning and patient preparation in male and females were evaluated. Results: There were 314 panoramic radiographs (81.5%) with errors. Errors related to the improper patient positioning were observed in 306 cases (78.5%). The most common error was palatoglossal air space (56.2%). There was no significant difference between males and females. Conclusion: The errors seen in panoramic radiographs were relatively high, thus training the operators is essential to maximize the quality of panoramic radiographs.