Mojtaba Azimian, A. Shahvarughi Farahani, Asghar Dadkhah, M. Fallahpour, M. Karimlu, Fatigue Severity Scale: The Psychometric Properties of the Persian-Version in Patients with Multiple Sclerosis, Research Journal of Biological Sciences, Volume 4,Issue 9, 2009, Pages 974-977, ISSN 1815-8846, rjbsci.2009.974.977, (https://makhillpublications.co/view-article.php?doi=rjbsci.2009.974.977) Abstract: As fatigue is highly prevalent and has a negative impact on quality of life and performance in a variety of disorders and Fatigue Severity Scale (FSS) is one of the most commonly used self-reported questionnaires to measure fatigue. The aim of this study was to evaluate different aspects of Validity and Reliability of the Persian-version of Fatigue Severity Scale (FSS-P) among people with multiple sclerosis. A sample of 50 people with Relapsing-Remitting type of multiple sclerosis and 30 Healthy Adult were included in this study. The participants were recruited from M.S clinic in Tehran between 2001-2007. The Fatigue Severity Scale (FSS) includes nine items developed to measure disabling fatigue and a Visual Analog Scale (VAS) to measure overall fatigue. A sample of asked to complete FSS and Short-form 36 Health Survey (SF-36) questionnaires. Test-retest reliability and Internal Consistency were assessed, using Intraclass Correlation Coefficient (ICC) and Cronbach's alpha, respectively. Dimensionality was assessed, using item-scale correlation after correction for overlap and convergent validity, using a priori hypothesized correlations with the SF-36. All the participants found the FSS-P to be clear and unambiguous in pilot testing. The ICC was reported 0/93 for the total score and 0/88 for VAS, The Cronbach's alpha was reported 0/96. The total score and the VAS were significantly correlated with the SF-36 vitality subscale (r = -0/69 and r = -0/73, respectively). Correlations with other SF-36 subscales were moderate (r = -0/43 to r = -0/65, all p<0.001). The results of the study revealed that the FSS-P is an appropriate instrument psychometrically to assess the people with multiple sclerosis. Keywords: Fatigue severity scale;multiple sclerosis;translation;validity;reliability;Iran