Cancer incidence statistics in the Russian Federation and the evidence from epidemiological and experimental studies suggest that the priority in primary prevention of cancer should be given to smoking control. Discontinuation of smoking may prevent in Russia annually about 80,000 cases of cancer, or about 25% of all newly diagnosed cases of cancer in 1989 (excluding skin squamous and basal cell carcinoma). Another very important direction of cancer prevention in Russia is modification of diet in favour of increased consumption of fresh fruit and vegetables. The elimination of occupational carcinogens or a decrease in exposure to them would result in an important decrease in the incidence of certain cancers in highly industrialized areas. A decrease in the exposure to carcinogens in ambient air and the protection from exposure to ionizing radiation are of some, although limited, importance in cancer prevention.