This paper describes the results of a survey designed to measure information levels on AIDS, defensive attitudes about AIDS, social rejection of AIDS carriers and AIDS sufferers, and understanding of AIDS-related vocabulary. The survey was carried out by means of a questionnaire administered to groups of juvenile offenders (n=43), trainee prison officers (n=25), drug abusers attending a drop-in centre (n=22) and university students (n=21). The level of information about the basic facts of AIDS was found to be encouragingly high in all 4 groups and, complementary to this, denial of the personal relevance of AIDS and defensive attitudes, which could lead to the avoidance of both communications on AIDS and preventative behavioural change, were found to be very low or non-existent among most subjects in all groups. However, there did appear to be as serious lack of knowledge about the role of sex in the spread of AIDS among a considerable minority of the subjects (up to 20% in some groups). While socially rejecting attitudes towards AIDS victims were generally absent, they were most common among the offenders and their presence was associated with a poor level of information on AIDS. A poor vocabulary or conceptual understanding regarding AIDS-related concepts was relatively widespread but was not necessarily linked to the lack of basic knowledge about AIDS.