OBJECTIVE: To assess the effect of early active shoulder movement after rotator cuff repair, compared to delayed active shoulder movement, on clinical outcomes, rotator cuff integrity, and return to work. STUDY DESIGN: Intervention systematic review. LITERATURE SEARCH: We searched 14 databases in November 2017 and updated the search in December 2018 and February 2020. STUDY SELECTION CRITERIA: We included comparative studies that assessed the effect of early active shoulder movement versus delayed active shoulder movement following rotator cuff repair. DATA SYNTHESIS: Means and SDs were used to calculate weighted mean differences and 95% confidence intervals for outcomes of interest. The sensitivity analysis included only randomized controlled trials and was performed when heterogeneity among studies was statistically significant. RESULTS: Eight studies with a total of 756 participants (early active shoulder movement, n = 379; delayed active shoulder movement, n = 377) were included. There was high-certainty evidence favoring early active movement for forward flexion (6 weeks), abduction (6 weeks), and external rotation (6 weeks and 3 and 6 months) postsurgery. There was moderate-certainty evidence of worse Western Ontario Rotator Cuff Index score (6 weeks) for the early active movement group, and no difference in rotator cuff integrity between the early and delayed active movement groups. There were no group differences for all other outcomes. CONCLUSION: Patients who commenced active shoulder movement early after rotator cuff repair had greater shoulder range of motion and worse shoulder-specific quality of life after surgery than patients who delayed active shoulder movement. However, the group differences did not appear to be clinically important, and rotator cuff integrity was similar. J Orthop Sports Phys Ther 2021;51(7):331-344. Epub 15 May 2021. doi:10.2519/jospt.2021.9634.