Introduction: Diagnosis of odontogenic cysts despite of their benign nature is a critical and challenging problem especially among undergraduate and postgraduate students. Aim: This study aimed to evaluate the capability of oral and maxillofacial surgery residents in diagnosing odontogenic cysts. Materials and Methods: This cross-sectional study was executed on 312 patient records over the past 20 years since October 1995 till December 2014 in Taleghani Hospital, Tehran, Iran. All recorded data was based on 2005 World Health Organization (WHO) classifications. The differential diagnosis was made by 65 residents based on clinical and paraclinical evaluations established in the charts. Differential diagnoses made by the residents were compared to the histopathological examination as the gold standard for identifying the nature of the cysts. Weighted kappa test was used to show the degree of agreement. Results: Data extracted from 312 records were analyzed. The mean age of examined patients was 27.6 years. The accuracy of diagnosis among the residents was moderate (kw=0.5). The diagnosis made by the residents was significantly related to the radiographic view of the cysts (p
