Cancer registries are one of the most important assets we have in improving the care of individual patients and in developing effective programs of cancer control. The hospital-based registry, through the accession and analysis of cancer cases seen in that hospital, provides information leading to the improvement of patient care. Information from the registry permits the evaluation of care given in that institution, serves as the basis for the continuing education of health care professionals in that hospital and stimulates the improvement of diagnosis and treatment. Second, the population-based central cancer registry accessions all cases of cancer in defined populations, allowing us to determine cancer patterns among various populations, monitor trends over time, guide the planning and evaluation of cancer control programs, help prioritize health resource allocations and advance clinical, epidemiological and health services research (1). Both types of registries are essential parts of the current system of cancer registration in the United States and in turn are critical elements in local and national cancer control programs.