It is now becoming generally recognized that an essential condition for alterations in our disease pattern is an extensive preventive campaign. One aspect of this consists in efforts to influence behaviour patterns in the population which are considered to be of significance for the development of disease. In order that preventive health behaviour be accepted, the persons who are at risk for development of the disease concerned must recognize their 'at risk' role with the behaviour norms associated with it in a manner similar to the acceptance of the sick role of sick people. Social psychological models have established a series of factors in attitude which should influence the acceptance of preventive health behaviour. A model of this type is reviewed and criticised. Formation of attitudes and awareness of disease are discussed on the basis of common experience in population groups as opposed to individual experience. Influence upon behaviour via social pressure from groups such as the family, fellow workers and friends are processes which should be recognized by health workers and should be considered when health education is planned. Social psychological theories have been criticised for not taking the structure and functions of the health system into consideration. As a basis for further studies, an epidemiological model is presented which takes into consideration interaction between the individual, the social environment and the characteristics of the offers for disease prevention from the health system. Finally, the relationship between health behaviour and community conditions is discussed also from studies in which particular interest was paid to the connection between socioeconomic grouping and preventive health behaviour. In contrast to a country such as China where health is a collective responsibility propagation of which is desirable for the entire community effective disease prevention is blocked in the west by alienation and defective solidarity. The necessity is emphasized of basing preventive health work on population groups rather than on individuals. Health workers must, together with other specialists, interest themselves in group processes, social networks and community structures in relation to awareness of disease, health behaviour and prevention of disease.