AbstractThe aim of this study was to analyse the influence of social representation on both social perceptions and social judgments. In the first stage of this study, 47 drug users and 80 ‘normal’ subjects were asked to respond to a questionnaire about representations of drugs. Three weeks later we contacted the same subjects. They were asked to answer some questions about a fictitious story in which an actor labelled as ‘a drug user’ or ‘a person’ disputed with a trader. Three different social representations of drugs were found. It was shown that these social representations were anchored in different social groups which were defined by their proximity to the world of drugs. Subjects who were themselves drug users shared an accepting or an ambivalent social representation of drugs but they also made the most negative judgements about the causes of a fictitious dispute between a trader and a drug addict. Moreover, these subjects had the most negative perception of the drug addict. Furthermore, some factors which increase the salience of social representations were studied. The effect on social perception and causal attributions of the interaction between social representations, the context and personal involvement in drugs was also shown. Some relations between the theory of social representations and the theories about asymmetrical intergroup relationships