PURPOSE To evaluate clinical response to treatment of calcified tendinitis of the shoulder by using a modified percutaneous ultrasonography (US)-guided fine-needle technique. MATERIALS AND METHODS Thirty shoulders of 30 consecutive patients (23 women, seven men; mean age, 47.4 years) with chronic shoulder pain (average duration, 43.1 months) refractory to medical treatment were treated percutaneously by using a fine needle and US guidance. Patients were prospectively evaluated by using a shoulder pain and disability index consisting of 13 items and divided into two subcategories: pain and disability. The patient completed the questionnaire before the procedure and during the follow-up visit approximately 1 month later. A diagnostic US examination was also performed at that time. RESULTS There was a statistically significant improvement in the shoulder pain and disability index total score (27.0%) and the pain (30.5%) and disability (23.9%) scores. According to the index, these results indicate a significant clinical response. CONCLUSION This modified US-guided fine-needle technique for calcified tendinitis of the shoulder appears to be an effective therapy and was less aggressive than previously described percutaneous techniques.