This study examined the validation and reliability of the Farsi version of the Duke University Religion Index (FDUREL), a brief measure designed to evaluate the primary dimensions of religiosity. The study was conducted in two phases. In the first phase, after translation of the original version of DUREL by using standard forward-backward translation, the FDUREL was administered to 427 medical students at different training levels. Reliability of the FDUREL was assessed by internal consistency and test-retest reliability. Principal components factor analysis was employed to assess the construct validity of the measure. In the second phase, 557 medical students were asked to fill out the FDUREL and Hoge Intrinsic Religiosity Scale to examine concurrent validity. The FDUREL was unidimensional and had good internal consistency and test-retest reliability. Results suggest that the FDUREL is a reliable and valid measure of religiosity in Farsi-speaking populations.