Introduction: Little information exists regarding the long-term outcome after structural failure of rotator cuff repair. We previously reported clinical improvement, despite a 94% rate of failure of healing, at two years of follow-up in a cohort of eighteen patients who had undergone arthroscopic repair of massive rotator cuff tears. The purpose of the present study was to evaluate the ten-year results for these patients with known structural failures of rotator cuff repairs. Methods: Fifteen (83%) of eighteen patients were available for follow-up at ten years. Patients were evaluated with use of the American Shoulder and Elbow Surgeons (ASES) score, the Simple Shoulder Test (SST), a visual analog scale pain score, and the Constant score. Radiographs and sonograms were assessed. Results: The average age was 74.6 years at the time of the latest follow-up. The average ASES score was 79.4 points (range, 50 to 95 points) and the average visual analog scale pain score was 2.2 points (range, 1 to 4 points); both scores were unchanged from those at two years. The average SST score was 9.2 points (range, 6 to 12 points), and the average age-adjusted Constant score was 73.2 points (range, 58.7 to 89.7 points). Of the patients with structurally failed repairs, all but one had radiographic signs of proximal humeral migration or cuff tear arthropathy: three had Hamada Grade-2 changes, five had Grade-3 changes, and three had Grade-4 changes (with two having Grade-4a changes and one having Grade-4b changes). Ultrasound confirmed the persistence of all tears that had been seen at two years. Conclusions: Clinical improvements and pain relief after arthroscopic rotator cuff repair of large and massive tears are durable at the time of long-term (ten-year) follow-up, despite early structural failure of repair. Shoulders had a high rate of progression of radiographic signs associated with large rotator cuff tears. These results demonstrate that healing of large rotator cuff tears is not critical for long-term satisfactory clinical results in older patients. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.