Incontinence is one of the most frequently encountered problems in multiple sclerosis (MS), and it has a negative effect on the daily lives of patients. Therefore, it is important to investigate this complaint and start appropriate treatment early. The aim of our study was to demonstrate the validity and reliability of the Turkish-language Incontinence Quality of Life Scale (I-QOL) in patients with MS. We included 37 patients with MS in this study. For analysis of test-retest reliability, we administered the Turkish-language version of I-QOL developed by a "translation-back translation" method to patients on the day of admission and 1 week after admission. To assess validity, we also evaluated patients with the Multiple Sclerosis Quality of Life Scale (MQOL-54) and Expanded Disability Status Scale (EDSS). We calculated the intraclass correlation coefficient of the I-QOL (total and all subscores) as 0.88 to 0.91 and the Cronbach alpha score as 0.88 to 0.91 (p < 0.05). We found a significant correlation among all subscores of I-QOL and physical and mental subscores of MQOL-54 and EDSS (p <0.05). Our study has demonstrated the internal consistency and reliability of the I-QOL in the Turkish language in patients with MS.