Objectives: The study aimed to evaluate the effects of the use of a shoulder sling, shoulder sling with a pillow, or not using a sling on the shoulder functional score and pain levels following arthroscopic rotator cuff tear repair. Patients and methods: This randomized prospective study was performed with 90 patients (49 males, 41 females; mean age: 56.2±12.2 year; range, 33 to 77 years) with a small-to-mid, full-thickness rotator cuff tear between July 2020 and October 2022. All patients underwent arthroscopic double-row repair. The nonsling group wore no sling, the sling group wore a sling, and the abduction pillow sling group wore a sling with an abduction pillow. The same rehabilitation program was performed. The Visual Analog Scale (VAS) score, Constant-Murley scores, and degrees of flexion and abduction were recorded preoperatively, on the 15th and 45th days, and at three months, six months, and one year. Results: On the 15th postoperative day, the VAS score was found to be significantly lower in the nonsling group. On the 45th day, the Constant-Murley score was found to be significantly higher in the abduction pillow sling group. There was no significant difference between the groups regarding the Constant-Murley scores at three weeks, six months, and one year. The shoulder forward flexion angle was significantly lower in the nonsling group on the 45th day. There was no significant difference between the three groups in respect of the shoulder forward flexion at three months, six months, and one year. Conclusion: No difference was determined between the groups at the six-month and one-year functional results. Not using a sling bandage can be recommended by reducing pain in the early postoperative period.