On the basis of 4 patients from our own records we describe the rare syndrome of "Hyperostosis sternocostoclavicularis". The etiology of this disorder is still unclarified. In addition to a swelling that is generally only slightly tender to pressure, the most important symptom is usually a long-standing, intermittent, dull pain in the upper sternum, the claviculae and the adjacent uppermost ribs. Laboratory diagnosis usually shows an accelerated blood sedimentation rate, but other laboratory findings are unremarkable and rheumatological serology gives a negative result. The changes detected by radiography are described, as are the histological findings. Primary or secondary malignant osteomas are also to be taken into account in differential diagnosis. For therapy most authors recommend medicinal treatment with non-steroidal antiphlogistic agents.