: Balance impairment and fear of falling are two common risk factors for falls in people with multiple sclerosis (PwMS). Clinicians should use valid, reliable, and responsive tools to assess these risk factors and identify individuals at increased risk for falls. So, this study aimed to examine psychometric properties of the Persian-version of the Activities-specific Balance Confidence (ABC) scale and Fall Efficacy Scale-International (FES-I) in Iranian PwMS. : One hundred and fifty-three PwMS completed the Persian versions of ABC, FES-I, Multiple Sclerosis Walking Scale-12 (MSWS-12), and Berg Balance Scale (BBS) in the first session. To assess the test-retest reliability, 50 PwMS filled out ABC, and FES-I in retest session with an interval of 2-7 days. Also, for evaluating responsiveness, 50 PwMS completed ABC and FES-I before and after a 4-week treatment. : Intra-class Correlation Coefficients were 0.96 and 0.93 and Cronbach's alpha coefficients were 0.96 and 0.99 for the ABC and FES-I, respectively. There were significant correlations ( < .001) between ABC and BBS (r = 0.55), FES-I and BBS (r = -0.56), ABC and MSWS-12 (r = -0.72), and FES-I and MSWS-12 (r = 0.76). No floor or ceiling effect was found. ABC and FES-I had acceptable responsiveness (AUC > 0.70), and their minimally important difference (MID) were 10.5 and 9.5 points, respectively. : The Persian-versions of ABC and FES-I are reliable, valid, and responsive measures to quantify balance confidence and fear of falling in PwMS at both clinical and research settings. The MID can help clinicians to make a decision based on the clinical significance of changes in patients' status.