OBJECTIVE To evaluate and compare the efficacy of 2 rehabilitation strategies after arthroscopic acromioplasty: supervised physical therapy focusing on strengthening exercises of the rotator cuff and scapula stabilizers (PT-group) vs home-based movement exercises (H-group). METHODS A randomized, single-blinded, clinically controlled study. METHODS Thirty-six patients entered the study. Thirteen in the PT-group and 16 in the H-group fulfilled all the assessments. METHODS For 12 weeks following surgery, patients performed either supervised physical therapy or home exercises. Follow-ups were conducted periodically for 6 months after surgery to evaluate shoulder function, pain (Constant-Murley (CM) and Disabilities of the Arm, Shoulder, and Hand (DASH) scores), and health-related quality of life. RESULTS The PT-group exhibited significantly greater improvements in CM (p =0.02) and DASH (p=0.05) scores. After treatment, the between-group mean difference in CM scores was 14.2 p (95% confidence interval 2-26). At the 6-month follow-up, the between-group mean difference in DASH scores was 13.4 p (95% confidence interval 0.1-23). CONCLUSIONS PT-supervised rehabilitation with strengthening exercises of the rotator cuff and scapula stabilizers seems to be superior to home exercises focusing on mobility for improving shoulder function after arthroscopic acromioplasty.