Objective: To assess the ability of functional measures to detect disease progression in dysferlinopathy over 6 months and 1 year. Methods: 193 patients with dysferlinopathy were recruited to the Jain Foundation’s International Clinical Outcome Study for Dysferlinopathy. Baseline, 6 months and 1 year assessments included: adapted North Star Assessment (a-NSAA), Motor Function Measure (MFM-20), timed function tests, 6 minute walk test (6MWT), Brooke Scale, Jebsen Test, manual muscle testing (MMT) and hand-held dynamometry (HHD). Patients also completed the ACTIVLIM questionnaire. Change in each measure over 6 months and 1 year was calculated and compared between disease severity (ambulant (mild, moderate or severe based on a-NSAA score) or non-ambulant (unable to complete a 10m walk)) and clinical diagnosis. Results: The functional a-NSAA test was the most sensitive to deterioration for ambulant patients overall. The a-NSAA score was the most sensitive test in the mild and moderate group while 6MWT was most sensitive in the severe group. The 10m walk test was the only test showing significant change across all ambulant severity groups. In non-ambulant patients, the MFM domain 3, wrist flexion strength and pinch grip were most sensitive. Progression rates did not differ by clinical diagnosis. Power calculations determined that 46 moderately affected patients are required to determine clinical effectiveness for a hypothetical 1 year clinical trial based on the a-NSAA as a clinical endpoint. Conclusion: Certain functional outcome measures can detect changes over 6 months and one year in dysferlinopathy and potentially be useful in monitoring progression in clinical trials.