Purpose of the Study: To define the role of ultrasonography in the diagnostic algorithm for patients with shoulder joint injury and to show its potential for the detection of rotator cuff tears and Hill-Sachs lesions., Material and Methods: A group of 52 patients with clinical signs of shoulder disorders following trauma who were treated in the 2005-2006 period. After ultrasonographic examination, all patients were surgically treated by arthroscopy. In 12 of them an additional magnetic resonance imaging was carried out before surgery. The results of ultrasonography were compared with arthroscopic findings in terms of detection of full-thickness rotator cuff tears and Hill-Sachs lesions. These were the two most frequent traumatic lesions detected by ultrasonography., Results: A full-thickness tear of the rotator cuff was correctly diagnosed in 13 patients. In further four the ultrasound finding was incorrectly interpreted as a moderate rotator cuff injury. For the detection of full-thickness tears, the sensitivity of the method was 76 %, its specificity was 94 % and accuracy 88 %. The detection of Hill-Sachs lesions by ultrasonography correlated with arthroscopic findings, with a sensitivity of 86 %, specificity of 93 % and accuracy of 92 %., Discussion: A number of studies report on options for the ultrasonographic detection of various types of traumatic injury to shoulder structures. Examination by ultrasound shows skeletal surfaces, thus permitting detection of a minor bone injury or a Hill- Sachs defect, and reveals soft tissue shoulder structures including tendons, ligaments and bursae. In some studies the possibility of detecting rotator cuff tears by ultrasonography has been described. Although sufficient accuracy of ultrasonographic examination in this region is reported, the results are not consistent., Conclusions: Our results show high reliability of ultrasonography for the diagnosis of shoulder trauma. The detection of full-thickness rotator cuff tears and Hill-Sachs lesions was possible with sufficient accuracy, which makes this quick, simple and available examination a valuable diagnostic tool. The finding of a rotator cuff tear is important information for the orthopaedist and, in the majority of patients, is also an indication for surgery. An ultrasonographic examination can therefore be regarded as a standard part of the diagnostic algorithm for shoulder trauma.