Behcet's disease (BD) is a chronic systemic inflammatory disease affecting multiple organs and systems such as mucosa, skin, eye, joints and cardiovascular, nervous and gastrointestinal systems. Various criteria are proposed for the assessment of BD. This study was designed to compare performance of two internationally collaborated criteria for diagnosis of BD, namely International Study Group (ISG) criteria and International Criteria for Behcet's Disease (ICBD) in the Azeri population of Iran.In a descriptive analytical study, 859 consecutive patients with one of the major clinical manifestations of BD were included. All patients were examined and evaluated by an expert rheumatologist and diagnosis was confirmed clinically. All patients were assessed by ISG and ICBD criteria. Finally, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of both criteria were calculated.We included 859 patients in this study. BD was diagnosed in 211 patients. Sensitivity, specificity and accuracy of ISG criteria were 64.9%, 100%, and 91.4%, respectively. Sensitivity, specificity and accuracy of ICBD criteria were 94.7%, 99.6% and 98.5%, respectively.Based on the finding of the present study, sensitivity and accuracy of ICBD criteria for diagnosis of BD in Azeri population are higher than ISG criteria. So we propose to use ICBD criteria for the evaluation of patients with suspected BD to decrease the rate of missed diagnosis.