Background and Objectives: The arthroscopic biceps rerouting (BR) technique was introduced as a novel technique for large-to-massive rotator cuff tears (LMRCT). This method can restore shoulder stability, and its biomechanical effect was verified in a cadaver experiment. Recent reports have shown favourable clinical outcomes. This study aimed to compare the clinical outcomes of partial repair with those of BR technique in LMRCT. Materials and Methods: We included 72 patients who had undergone LMRCT. Arthroscopic partial repair was performed in 31 patients (group I), while repair with the BR technique was performed in 41 patients (group II). Functional and imaging outcomes were evaluated and compared using a visual analogue scale for pain, range of motion (ROM), American Shoulder and Elbow Surgeons (ASES) score, Constant score, and Korean Shoulder Score (KSS) before the surgery and at 3, 6, and 12 months after the surgery and at the last follow-up. Tendon integrity was investigated using magnetic resonance in all the patients at 12 months postoperative. Results: Mean follow-up period was 22.11 ± 10.47 months (range, 12–53 months). Forward flexion (P=0.02) and external rotation at the side (P=0.04) were significantly higher in group II than in group I on postoperative day (POD) 12. For internal rotation, group II showed significant improvement compared to group I on POD 3 (P=0.002) and at six months postoperative (P=0.01). On POD 12, the ASES (P=0.047) and KSS (P=0.048) were better in group II. Significant improvements in pain and clinical scores were observed in both groups at the last follow-up. However, there were no significant differences in pain, clinical scores, or ROM between the two groups at the last follow-up. Retear of the repaired tendon was observed in nine patients in group I (29.03%) and 8 in group II (19.51%, P = 0.35). Conclusions: Partial repair and repair using the BR technique effectively improved clinical and radiologic outcomes. The BR technique revealed early recovery of ROM and better clinical results than partial repair until one year postoperatively. This could be a useful method in LMRCT.