Sequential computerized tomography (CT) allows us to determine the growth rate of acoustic neuromas. Prior to CT scanning, a variability in tumor growth rates was recognized on the basis of clinical signs. After incomplete tumor removal, some patients experienced rapid recurrence, whereas others lived many years without recurrence. We used CT scanning to study tumor growth rates in a heterogeneous group of 21 patients. Thirteen elderly patients were given annual scans after incomplete tumor removal, while eight patients who had not had surgery are likewise being followed up. Early detection and complete tumor removal with preservation of hearing and facial function remain the goal in vigorous and healthy patients. However, a large number of older, infirm patients with acoustic neuromas may not require surgery or be candidates for incomplete tumor removal. Because rapid tumor growth may necessitate total tumor removal even in older patients, a better understanding of the growth rates may permit us to take a more scientific approach in planning these patients' management.