The aim of this study was to assess the validity and reliability of the Turkish version of the Fatigue Severity Scale (FSS) in Parkinson's disease (PD) patients for use in clinical settings. A consecutive 106 patients with PD were included in the study. The Turkish version of FSS was analyzed for reliability (internal consistency and reproducibility) and validity (convergent and discriminant). The Turkish version of FSS yielded an acceptable internal consistency (Cronbach's alpha = 0.960 and corrected item-total correlations: 0.761-0.891), and it was established as reproducible (test-retest intraclass correlations for items: 0.887-0.936). The FSS total score was correlated significantly with PD-related variables. Between-group differences on both items and the total score of FSS by modified Hoehn and Yahr staging were found to be statistically significant. The present study has shown that the Turkish version of the FSS is a valid and reliable tool for the assessment of fatigue in PD patients. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.