240 patients undergoing arthroscopic rotator cuff repair were randomized to receive either enhanced recovery after surgery (ERAS) with an interscalene block (ERAS + ISB; n=80), surgery + ERAS (n=80), or surgery only (n=80). The primary outcome of interest was pain on a Visual Analog Scale (VAS). Secondary outcomes of interest included length of stay, constant shoulder score, University of California-Los Angeles (UCLA) scores, and the incidence of joint stiffness and swelling. The ERAS + ISB group exhibited the most effective pain control and shortest hospital stay, outperforming the surgery + ERAS group, which surpassed the surgery-only group. While the surgery + ERAS and ERAS+ISB groups showed better shoulder function scores than the surgery-only group at 6 weeks and 3 months postoperatively, no significant differences were found between them. Postoperative joint swelling was significantly higher in the surgery-only group than in the other two treatment groups, although postoperative stiffness did not vary significantly among the groups.