Achievement of NIH and ACS goals for reduction in cancer mortality will require increased efforts directed at risk reduction and early detection in the general population. Primary care providers will play a major role. This paper describes the development and use of a quantitative cancer-risk appraisal tool designed to promote cancer prevention and screening and provide a framework for advancing education on these critical issues at all levels of medical training, to assist physicians in risk identification and patient counseling. The risk assessment questionnaire is close-ended and easily completed by the patient within 10 to 15 minutes. The IBM-compatible format permits easy quantitation by laser scanning and computer analysis. This program quantitates risks arising from interacting independent factors and estimates the effects of primary prevention interventions. Program output includes age- and sex-specific ACS screening guidelines and discussion of intensified screening measures in high-risk subjects.