© 2016 Elsevier B.V. Background Knowledge regarding physical activity (PA) and its benefits in pediatric onset multiple sclerosis (POMS) is growing and suggests high levels of inactivity. The utility of a validated screening tool for clinical settings is unknown. This study evaluated the Godin Leisure-Time Exercise Questionnaire (GLTEQ) as a measure of PA in POMS. Methods POMS patients (n=27) and healthy controls (n=45) wore an accelerometer over a 7-day period and then completed the GLTEQ. Results The GLTEQ captured expected group differences in PA for vigorous, moderate, and moderate-to-vigorous physical activity (MVPA), confirmed by accelerometry. There was a large, positive correlation between GLTEQ and accelerometry scores for vigorous PA in POMS (r=0.736, p=0.001), and a nearly significant and moderate, positive correlation between MVPA scores (r=0.319, p=.053). Conclusion We provide evidence that supports the validity of GLTEQ scores as measures of vigorous and MVPA in POMS. Researchers and clinicians might adopt this scale for measuring PA.