Most lesions of the clavicle are traumatic and pose few diagnostic difficulties. Nontraumatic clavicular lesions, on the other hand, are rare and frequently present problems in diagnosis. This report reviews the clinical, radiologic, and bacteriologic findings in ten patients, six of whom were diagnosed as having acute osteomyelitis and four chronic osteomyelitis. The differential diagnosis of clavicular osteomyelitis is also discussed. The clinical duration of the infectious process in these patients ranged from 2 weeks to 1.5 years. All patients presented with pain; six had fever, three had localized swelling or a mass, and three had soft tissue abscesses. The radiographic findings also varied: the lesion was predominantly sclerotic in four patients, lytic in three, and mixed in two patients; in the one patient in whom magnetic resonance imaging was the only imaging study performed, these features could not be properly evaluated. Periosteal reaction was detected in three patients. Staphylococcus aureus was the causal organism in four patients, while in the remaining six patients different microorganisms were cultured, including Coccidiodes immitis and Mycobacterium tuberculosis. Six patients required biopsy for final diagnosis. Although clavicular osteomyelitis is rare, particularly in adults, it should be considered in the differential diagnosis of a clavicular lesion. The final diagnosis often depends on the results of biopsy and cultures.