Opiate addiction is associated with decision-making deficits and we previously showed that the extent of these impairments predicts aspects of treatment outcome. Here we aimed to establish whether measures of decision-making performance might be used to inform placement matching. Two groups of opiate dependent individuals, one receiving treatment in a community setting (n=48) and one in a residential setting (n=32) were administered computerised tests of decision-making, impulsivity and planning shortly after the beginning of treatment, to be followed up three months into each programme. In the community sample, performance on the decision-making tasks at initial assessment predicted abstinence from illicit drugs at follow-up. In contrast, in the residential sample there was no relationship between decision-making and clinical outcome. Intact decision-making processes appear to be necessary for upholding a resolve to avoid taking drugs in a community setting, but the importance of these mechanisms may be attenuated in a residential treatment setting. The results support the placement matching hypothesis, suggesting that individuals with more prominent decision-making deficits may particularly benefit from treatment in a residential setting and from the inclusion of aspects of cognitive rehabilitation in their treatment programme. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.