To determine the concordance and statistical precision in gait velocity in people with multiple sclerosis (pwMS), measured with FeetMe® (insoles with pressure and motion sensors) compared with GAITRite® (classic reference system of gait analysis) in the timed 25-Feet Walk test (T25WT). This observational, cross-sectional, prospective, single center study was conducted between September-2018 and April-2019 in pwMS aged 18-55 years, with Expanded Disability Status Scale (EDSS) 0-6.5 and relapse free ≥30 days at baseline. Primary endpoint was gait velocity. Secondary endpoints were ambulation time, cadence, and stride length assessment, while the correlation between gait variables and the clinical parameters of MS subjects was assessed as an exploratory endpoint. A total of 207 MS subjects were enrolled, of whom, 205 were considered in primary analysis. Most subjects were women (66.8%) and had relapsing-remitting MS (RRMS) (82.9%), with overall mean (standard deviation SD) age of 41.5 (8.0) year and EDSS 3.1 (2.0). There was a statistically significant (p<0.0001) and strong agreement (intra-class correlation coefficient (ICC) >0.830) in gait velocity, ambulation time and cadence assessment between FeetMe® and GAITRite®. Agreement between devices was strong (ICC≥0.800). FeetMe® is the first validated wearable medical device that allows gait monitoring in MS subjects, being potentially able to assess disease activity, progression, and treatment response.