BACKGROUND: Measuring ataxia severity is primarily conducted in-person using tests such as the Scale for the Assessment and Rating of Ataxia (SARA). However, given the motor and cognitive impairments of people with cerebellar ataxia (PwA), there are major limitations in ensuring the assessment is accessible and scalable. We aimed to develop and validate a novel test, enabling the remote assessment of ataxia severity, SARA-Le (SARA Live e-version). METHODS: SARA-Le is a structured step-by-step test for administering the SARA through video conferencing. In two experiments, we administered SARA-Le to 106 PwA. In Experiment 1 (n = 23), we assessed concurrent validity by comparing SARA-Le and in-person SARA scores administered by an independent neurologist. In addition, we evaluated associations between nine gait measures and both SARA and SARA-Le scores. In Experiment 2 (n = 83), we assessed the efficacy, internal consistency, and correlations between SARA-Le and other related measures. RESULTS: First, we found a high correlation (r = 0.89, P = 0.002) between SARA-Le and in-person SARA scores, supporting convergent validity. Second, SARA-Le and SARA scores were both similarly associated with the nine gait measures, supporting construct validity. Third, SARA-Le's Cronbach's alpha was very high (0.831), supporting internal consistency. Fourth, SARA-Le scores exhibited a positive correlation with disease duration (r = 0.44, P <
0.002), and a negative correlation with MoCA scores (r = - 0.27, P = 0.007), supporting construct validity. CONCLUSIONS: SARA-Le can serve as a remote technology-based protocol, improving the accessibility and scalability of ataxia severity evaluation.