A cross-sectional survey of all patients aged 30-65 in four general practices within one Local Health Care Co-operative in Fife, Scotland was undertaken to measure the prevalence of family history of colorectal, breast and ovarian cancer. A total of 7619 patients aged 30-65 responded to a postal questionnaire (response rate 59%). In all, 17% of respondents (1324, 95% Cl 16-18%) reported a relative affected by colorectal, breast or ovarian cancer. Of those, 6% (78, 95% CI 5-7%) met the Scottish guidelines for referral for genetics counselling. In all, 2% (24, 95% CI 1-3%) of all individuals with an affected relative had received genetic counselling and risk assessment. Of these, 25% (6, 95% CI 8-42%) met the moderate- or high-risk criteria for developing a cancer. In conclusion, the number of patients who are at a significantly increased risk of cancer on the basis of a family history is small (approximately 10 per General Practitioner (GP) list). It is therefore unrealistic to expect GPs to develop expertise in genetic risk estimation. A simple family history chart or pedigree is one way that a GP can, within the constraints of a GP consultation, determine which patients should be reassured and which referred to the local cancer genetic clinic.