BACKGROUND: Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease in children, closely linked to the rise in pediatric obesity. Physical activity (PA) is critical for MASLD management, yet many children fail to meet PA guidelines due to various barriers. This study quantifies PA levels and identifies barriers in Canadian children with MASLD. METHODS: This prospective cohort study included 25 pediatric MASLD patients (≤ 18 years) recruited from a tertiary care center between spring and fall 2023. Participants completed the Habitual Activity Estimation Scale (HAES) and a modified PA Barrier Survey. Clinical, demographic, and laboratory data were collected. RESULTS: The median age was 13 years, with 64% male participants. While 96% recognized the importance of PA, only 56% met the WHO-recommended 60 min of daily moderate-to-vigorous PA. Barriers included fatigue (84%), discomfort (56%), fear of injury (32%), and ridicule (36%). Participants who met PA guidelines were more likely to feel supported by healthcare providers (79% vs. 45%). Moderate technology use (52% used activity trackers) suggests potential for greater integration to boost engagement. CONCLUSION: Children with MASLD face significant barriers to PA despite high awareness of its benefits. Tailored strategies incorporating technology and healthcare support are essential to improving PA adherence. Future research should explore larger cohorts and the influence of socioeconomic and cultural factors on PA behaviors.