We have presented a case of an osteoma of the clavicle in a 41-year-old man. The possibility of alternate diagnoses--in particular, ancient osteochondroma, posttraumatic hyperostosis, and parosteal osteosarcoma--was addressed. However, the pathological examination was most consistent with the diagnosis of osteoma. This benign bone lesion is most often found in the calvarium, jaw, and face. Osteomas of long bones remain extremely rare, except in the setting of Gardner's syndrome.