Lipoma is the most common soft tissue tumor, but among the rarest tumors of the bone. The first case, reported by Cornil and Renvier in 1868 was a lipoma in the diaphysis of the femur. In Korea, 12 cases of intraosseous lipoma have been reported. A 42-year-old woman presented with a radiolucent lesion that was well marginated, lobulated, and had a sclerotic border by radiographic findings of the proximal humerus taken after a traffic accident. Magnetic resonance imaging and biopsy were performed for diagnosis. Histologically, the lesion was compatible with intraosseous lipoma. Intralesional curettage with a bone graft was performed. No recurrence was evident at the 1 year follow-up. We report a case of intraosseous lipoma that arose in the proximal humerus and include a review of the literature.