After briefly reviewing the shoulder impingement syndrome, the authors investigate the role of two diagnostic imaging methods, i.e., ultrasonography (US) and arthrography, in demonstrating the typical features of this condition. Over a 15 months' period, 190 patients suffering from shoulder pain were examined with arthrography; 50 of them subsequently underwent acromion plastic surgery and rotator cuff stitching. This study was aimed at comparing US and arthrographic results, applying classifiable criteria to make the most accurate diagnosis of rotator cuff tears. The lack of visibility of the rotator cuff at US was the major and clearest sign of tear (100% of cases). The association between cuff thinning and hypo/hyperechoic damaged focal areas was another major sign (in 76.19% of complete tears and in 14.28% of incomplete tears). Hyperechoic focal areas alone proved to be a false-positive finding in 5 cases, while in 11 of 19 cases normal US patterns were a false-negative finding; in 3 cases other conditions were diagnosed. To conclude, the value of US is emphasized in the screening of the painful shoulder and the use of arthrography is suggested when both clinical tests and US fail to yield enough information for a diagnosis to be made.