Five cases of axial skeletal osteoid osteomas were viewed with particular attention to the role of computed tomography (CT) as a key diagnostic tool in the evaluation of osteoid osteoma. The complex anatomy of the axial skeleton can make the diagnosis of osteoid osteoma extremely difficult on routine films or tomograms, and the lesion often is well delineated only on CT scans. As complete surgical excision of this benign bony tumor is curative, precise anatomic localization is essential to the surgeon. The unique cross-sectional display of CT of the axial skeleton provides the surgeon with the exact location and extent of the lesion, which may allow a more limited surgical resection of the involved bone by defining the optimal surgical approach or procedure. Conventional radiographs were normal in all patients. Bone scans were positive when obtained and were useful in localizing the lesion and directing CT to the appropriate level. In all five cases CT was of proven value in accurately demonstrating the location, nidus, and other characteristic diagnostic radiographic features of osteoid osteoma.