OBJECTIVES: To assist family physicians in stratifying women with a family history of breast cancer as being at low, moderate, or high risk of hereditary breast cancer (HBC). To present guidelines for managing each of these risk groups. QUALITY OF EVIDENCE: A MEDLINE search was conducted from January 1976 to December 1997 using key words related to breast cancer risk factors, risk assessment, prevention, and screening. Risk stratification criteria were derived empirically and assessed using retrospective chart review. MAIN FINDINGS: Although up to 20% of women in the general population have a family history of breast cancer, less than 5% are at high risk for HBC. Certain features in a family history suggest increased risk. Women with none of these features are at low risk for HBC and should have annual clinical breast examinations and mammography at least every 2 years starting at age 50. Women with one or more features of increased risk who do not meet criteria for referral to a familial cancer clinic are at moderate risk for HBC and should begin annual mammography and clinical breast examination at age 40. Women who meet referral criteria are at high risk for HBC and should be counseled regarding referral to a familial cancer clinic for more detailed risk assessment and consideration for genetic testing. All women should be taught proper breast self-examination technique and encouraged but not pressured to practise it monthly for life. CONCLUSION: A simple algorithm can assist physicians in stratifying women into low, moderate, and high HBC risk groups. Management strategies for each group are given in this article and the two following (Heisey et al page 114 and Carroll et al page 126).