Studies using samples of alcoholics and cigarette smokers show that the occurrence of the abstinence violation effect predicts the likelihood of a full-blown relapse following an initial slip from voluntary abstinence. The present study investigated this process in a sample of 31 illicit drug users. The attributional styles of abstainers and relapsers were examined in addition to the types of initial slip situations for the relapse group. No significant differences were found in attributional styles, although relative to the relapse group there was a tendency for abstainers to score higher on internality and stability of attribution for negative events, but lower on globality. Both negative affect and interpersonal conflict, but not social pressure, were found to be important precipitants for relapse. Demographic differences between the groups are discussed in addition to the implications of the results for models of relapse, prediction of relapse and cognitive therapy in relapse prevention.