Over the past 14 years, since the discovery of the first gene for breast cancer (BRCA1), cancer genetics has become an increasingly important part of the workload of clinical genetics services, now accounting for approximately half of all referrals. Such referrals may occur for a number of different reasons – where a healthy patient is concerned that their family history of cancer places them at a significant risk of cancer themselves; where a patient with cancer is worried about the risk of cancer to their relatives; where a clinician feels that a patient has a strong family history that suggests a genetic predisposition; and where a clinician feels that a patient has an unusual form of cancer that suggests a genetic predisposition.The role of the clinical geneticist is to assess cancer risk, develop individualised management strategies for those at increased risk of cancer, offer genetic testing if appropriate and facilitate family communication.