This prospective, randomized study was performed to evaluate the results of mini-open and arthroscopic rotator cuff repair in a comparative case series of patients followed for 24 months. A total of 125 patients were randomized to mini-open (Group I) or arthroscopic (Group II) rotator cuff repair at the time of surgical intervention. The University of California Los Angeles (UCLA) score, the American Shoulder and Elbow Surgeons (ASES) index, and muscle strength were measured to evaluate the clinical results, while magnetic resonance arthrography was used at 24-month follow-up to investigate the postoperative rotator cuff integrity. Fifty-three patients in Group I and 55 patients in Group II were available for evaluation at 24-month follow-up. At 24-month follow-up, the UCLA score, the ASES index, and muscle strength were statistically significantly increased in both groups postoperatively, while no significant difference was detected between the 2 groups. Intact rotator cuffs were investigated in 42 patients in Group I and 35 in Group II, and there was a significant difference in postoperative structural integrity between the two groups (P < 0.05). When analysis was limited to the patients with full-thickness tear, the muscle strength of the shoulder was significantly better in Group II, and the retearing rate was significantly higher in Group II. Based on the results obtained from this study, it can be indicated that arthroscopic and mini-open rotator cuff repair displayed substantially equal outcomes, except for higher retearing rate in the arthroscopic repair group. While for patients with full-thickness tear, arthroscopic rotator cuff repair displayed better shoulder strength and significantly higher retearing rate as compared to mini-open rotator cuff repair at 24-month follow-up.