51 patients (56 shoulders) with subacromial impingement syndrome were randomized to receive a subacromial corticosteroid injection, either with or without ultrasound guidance. The purpose of this study was to determine if ultrasound-guided corticosteroid injection resulted in significantly improved post-treatment pain, function, patient satisfaction and range of motion when compared to 'blind' injection (standard corticosteroid injection administered with the aid of anatomical landmarks). Results suggested that ultrasound imaging provided no significant clinical benefit when compared to blind injection, as evidenced by comparable outcomes both immediately after administration and after a follow-up period of 6 weeks.