Abstract The attitudes, beliefs and expectations of the addict have received suprisingly little research attention. The present study looks at the relationship between the addict's perception of their own drug taking and their behaviour in treatment. The subjects who took part in the study were receiving treatment at a London drug dependence unit: 60 were inpatients, 40 were outpatients. All completed an attitude questionnaire and a personality inventory, (the EPQ). Several attitudinal differences were found between inpatient and outpatient groups, the outpatients being more generally resistant to the prospect of giving up drugs. Among the inpatients, those subjects who saw their addiction as a sort of sickness were least likely to remain in treatment. The attitude items related more clearly to the addict's behaviour in treatment than did the personality measures. The implications of these findings for the treatment of drug addicts are discussed.