Primary prevention represents an effective instrument in the battle against tumour diseases. Prevention is aimed to lower the mortality for this disease by means of reduction of the cancer incidence. Our article reviews the main fields of primary prevention, namely the principles of proper nutrition and regimen. Effects of balance in energy and related nutrients, essential components of the diet, types of meals together with problems of food processing and storage are discussed from the view of the cancer prevention. Each chapter brings applicable preventive recommendations. Smoking is considered as a risks factor not only for tumours, but also for other serious diseases. Other carcinogenic factors and possible preventive measures are referred in the last chapter. Though we know that the primary cancer prevention requires active approach of the whole society, we are certain that medical professionals in every day contact with patients can highly improve the public informedness. The article submits substrate for such discussions.

        Key words: primary prevention, risk of cancer, malignant tumour, smoking habit.