RESUMEN
To validate Persian version of the FSFI and to determine its diagnostic cut off score. This was a descriptive analytic study. To fill in the Persian version of the FSFI. In addition clinical interviews were carried out by a psychiatrist on DSM-4 criteria. Women divided in two age and educational matched groups: the control group [n=28] who have not sexual dysfunction and the case group [n=53] who have sexual dysfunction. Data were analyzed by Cronbach's alpha and validity was assessed by comparing mean scores of two groups. Optimal cut off score determined by Receiver Operating Characteristic [ROC] curve. The findings showed satisfactory results for full scale and each subscale with Cronbach's alpha ranging from 0.66 or above for sexually dysfunctional sample and 0.70 or above for sexually active sample. Discriminant validity confirmed the ability of both total and domain scores to differentiate between active and inactive women. On the basis of sensitivity and specificity analyses we found that the optimal cut off score was found to be 28 for differentiating women with and without sexual dysfunction. The findings showed that the Iranian version of Female Sexual Function Index [FSFI] is a reliable and valid instrument for measuring sexual function in women