Computed tomography was performed in 100 patients for additional evaluation of suspected skeletal metastases following radionuclide bone scanning in 86 patients and conventional radiography in all. A retrospective review of these cases revealed that the majority (78%) involved the spine and pelvis. Computed tomography contributed to the diagnosis of a malignancy by revealing a definite destructive lesion of bone in 27 patients who had an abnormal radionuclide bone scan, a normal or inconclusive radiograph, or both. It excluded a malignant lesion in 19 patients. In 38 patients, computed tomography provided additional information that contributed to such aspects of patient care as obtaining tissue diagnosis, determining the extent of lesions, and evaluating the response to treatment. False diagnoses were made in two patients. Detection by computed tomography of a skeletal lesion and histologic documentation, frequently by computed tomography-guided percutaneous needle aspiration biopsy, greatly curtailed an otherwise extensive search for the primary site. Furthermore, this information altered the treatment plan by obviating the need for radical resection or biopsy of the primary tumor and by directing the choice of an appropriate chemotherapeutic regimen.