46 patients with subacromial impingement were randomized to receive a 6-week program of either home-based or supervised exercise therapy. The goal of this study was to compared outcomes of shoulder pain, disability, and range of motion between groups, as evaluated up to 26 weeks after the initiation of treatment. Results of this study demonstrated no significant difference between groups for pain, disability or shoulder range of motion. The incidence of persistent clinical signs of subacromial impingement (minimum 2 of 3 positive tests for infraspinatus test, ainful arc test, and Kennedy-Hawkins test) at 6 weeks was significantly lower following supervised versus home-based therapy.