Aims: The roentgenologic morphology of symptomatic calcified deposits of the rotator cuff can be classified according Gärtner (1993, Z Orthop Ihre Grenzgebiete 131: 461–469). This classification influences therapeutic procedures and prognosis of clinical outcome in these patients. In the present study intraoberserver-reproducibility and interobserver-reliability of Gärtner’s classification were tested. Methods: Plane radiographs of 100 patients with calcifications of the supraspinatus tendon were classified according the criteria of Gärtner by six independent observers twice within four months. Intrao-berserver-reproducibility and interobserver-reliability were calculated by means of Cohen’s-kappa-index. Results: Kappa-values of intraoberserver-reproducibility had a mean of 0.4208 (SD 0.1299), kappavalues of interobserver-reliability were 0.490 for the first and 0.474 for the second classification. Conclusions: Determination of intraoberserverreproducibility gave insufficient to satisfactory results, interobserver-reliability was sufficient. The clinical use of Gärtner’s classification to plan therapeutic procedures or to determine clinical prognosis in patients with calcifying tendinitis can be recommended only with limitations.