Rotator cuff tears are a prevalent cause of shoulder dysfunction, with full-thickness tears significantly impairing mobility and quality of life. While arthroscopic rotator cuff repair (ARCR) has demonstrated positive outcomes, there is ongoing debate regarding its long-term efficacy, re-tear rates, and functional recovery. This randomized controlled trial (RCT) evaluates the efficacy of ARCR in patients with full-thickness rotator cuff tears by assessing pain reduction, functional improvement, and structural integrity post-surgery. A total of 120 patients diagnosed with full-thickness rotator cuff tears were randomly assigned to either the ARCR group or the conservative management group. The primary outcomes were measured using the Visual Analog Scale (VAS) for pain and the Constant-Murley Score (CMS) for shoulder function at 6 and 12 months post-intervention. Secondary outcomes included re-tear rates, range of motion (ROM), and patient satisfaction scores. Patients undergoing ARCR showed a statistically significant improvement in CMS (mean ± SD: 85.6 ± 7.8) compared to the conservative group (67.3 ± 8.4, p<0.001). Pain reduction was superior in the ARCR group (VAS score: 1.8 ± 0.9 vs. 4.7 ± 1.2, p<0.001). MRI evaluation at 12 months revealed a re-tear rate of 18.3% in the ARCR group versus 36.7% in the conservative group (p=0.007). These findings confirm that ARCR provides superior functional recovery, pain relief, and reduced re-tear rates compared to conservative treatment in full thickness rotator cuff tears.