Objectives: To determine the test-retest reliability and validity of the Lower Extremity Motor Activity Log (LE-MAL) for assessing LE use in the community in adults with multiple sclerosis (MS). Design: Prospective analysis of measures conducted by trained examiners. Setting: Participants were evaluated by telephone on several measures of LE use. Participants: Adults with MS (N=43). Interventions: Not applicable. Main Outcome Measures: The LE-MAL has 3 subscales (Assistance, Functional Performance, and Confidence). It was administered twice, at least 2 weeks apart. The Multiple Sclerosis Walking Scale (MSWS-12), Patient Determined Disease Steps (PDDS), and Mobility Scale were only administered during the first call. Results: The test-retest reliability of the composite and the 3 subscale LE-MAL scores were high (intraclass correlation, >0.94). The composite and subscale LE-MAL scores were strongly correlated with the MSWS-12, PDDS, and Mobility Scale scores (r=–0.56 to –0.77; P<.001). Conclusion: This initial study suggests that the LE-MAL reliably and validly measures LE use in the community in adults with MS.