A technique of computed tomography with intravenous contrast has proven useful in the differentiation between osteoid osteoma and other similar appearing lucent lesions of bone in 6 cases. The clinical evaluation of benign appearing radiolucent lesions of long bones has been greatly improved by the use of modern imaging techniques. The differential diagnosis often is narrowed to osteoid osteoma and osteomyelitis based on plain radiographs, computed tomography, or magnetic resonance imaging. The enhancement of the lucent center of the lesion was plotted against time. The rapid uptake of contrast medium by the osteoid osteoma was in sharp contrast to the much slower enhancement in osteomyelitis. The establishment of a preoperative diagnosis enabled the surgeon to excise the lesion without a biopsy. Histologic review verified the preoperative diagnosis in all cases.