The aim of this study was to examine the self-efficacy of outpatient drug heroin and alcohol abusers in treatment for their addiction, using the theoretical models proposed by Bandura and Annis. The sample consisted of 162 participants, who were assigned to one of three treatment groups: methadone, drug-free and alcohol. The Self-Efficacy Scale (Sherer et al., 1982), the Inventory of Drug-Taking Situation (IDTS; Annis & Martin, 1985) and the Interview for Research on Addictive Behavior (EICA; López-Torrecillas, 1996) were used to assess them. Methadone and the drug-free groups had higher scores of self-efficacy (general and total score) than the alcohol group. Methadone group showed lower scores in situational confidence that free drug and the alcohol groups, the latter showing highest scores. The results suggest that the models refer to different aspects of self-efficacy. More research is necessary to analyze the nature of this difference.