A prospective health-education research project about AIDS knowledge and attitudes towards AIDS was conducted in Athens and nine adjacent municipalities in west Attica, Greece. Socioeconomic and demographic data, AIDS knowledge, and attitudinal information were collected from 1552 respondents and analysed treating the attitudes of stigmatization, discrimination and fear towards AIDS as the dependent variable. Statistically significant correlations were found between each of the three attitudinal variables and the independent ones; specifically, age, place of residence, marital status and level of AIDS knowledge. Our working hypothesis--that the higher the level of AIDS knowledge, the lower the level of discrimination and stigmatization--was supported by our data. The relationship between AIDS knowledge and fear was less clear. Fear probably inhibits a rational approach to screening for HIV, and more empirical research is needed about fear and its interaction with stigmatizing and discriminatory attitudes and behaviours. Such research should be aimed at identifying population groups 'at risk' of expressing high levels of negative social attitudes about AIDS so that educational programmes can be appropriately designed.