Each year in the United Kingdom there are over 300,000 new cases of cancer and nearly 165,000 deaths from cancer. It is widely believed that as many as four fifths of all cancers are preventable by means that are already available. The Health of the Nation and the Europe Against Cancer programme have set targets and strategies for reducing the risk of cancer. An approach based on the whole population will achieve the greatest reductions in morbidity and mortality. Complementary to this is the individual approach, which can be based in primary care and targeted at high risk subjects. Health promotion and screening in primary care are not in themselves self evidently valuable. Their effectiveness must be tested rigorously and scientifically. Furthermore, because of limited time and resources, health education in primary care should be focused on interventions that are likely to achieve the greatest benefit, such as helping people to stop smoking.