The presence of a family history of cancer of the colorectum, breast, uterus and ovary is associated with an increased risk for that type of cancer. The aim of this study was to assess the prevalence of a family history of these cancers in the community. Nurses asked all attenders at health checks aged 35-64 about the presence of a history in close relatives of cancer diagnosed under the age of 70. Information was obtained from 8109 patients. Of the sample, 3.1% had a family history of colorectal cancer; 4.8% of women had a family history of breast cancer, whilst 1.9% had a family history of uterine or ovarian cancer. Projecting the results to a population of 2000 demonstrated that a general practitioner with a list size of 2000 could expect to have 30-40 patients in whom an appropriate management strategy would need to be considered.