OBJECTIVE: The purpose of this study was to find out the usefulness of ultrasonographic evaluation in shoulder impingement syndrome. METHOD: The patients with positive impingement sign (49 patients) at shoulder joint were evaluated. The Ultrasonograms of shoulder were performed at first visit and 4 weeks later. The patients who showed abnormal findings were treated with subacromial steroid injection. In order to check the efficacy of injection, we also used questionnair which consist of active range of motion, shoulder pain score, and visual analogue scale. RESULTS: 16 among 49 patients (32.7%) had abnormal ultrasonograms as follows; only fluid collection in subacromial bursa was shown in 3 patients (6.1%), only fluid collection in biceps long head tendon sheath in 4 (8.2%), partial thickness tear of supraspinatus tendon (SSP) in 6 (12.2%), and full thickness tear of SSP in 3 (6.1%). Follow-up ultrasonograms were performed after subacromial steroid injection on 4 patients and 3 among the 4 patients showed marked improvement ultrasonographically. 23 among 49 patients were recruited and showed marked improvement in each questionnaire. CONCLUSION: Ultrasonography gave good information in management of impingement syndrome furthermore it could be used as a primary imaging technique evaluating rotator cuff disease.