The purpose of this study was to determine the accuracy of ultrasonography in the detection of rotator cuff tears. In a prospective study of 41 patients, the ultrasound results could be compared with the combined results of (CT) arthrography, arthroscopy and operation. The sensitivity of sonography in detecting partial and total rotator cuff tears was 86%, the specificity 91%, the positive predictive value 96% and the negative predictive value 73%. In spite of the relatively small size of this series, our results are comparable with those of most other studies. Based on these results, sonography can provide a non-invasive, rapid and inexpensive diagnostic method for screening patients with shoulder complaints. A disadvantage of the method is its long learning curve.