BackgroundThe Drug-Taking Confidence Questionnaire evaluates a drug user’s confidence in his or her ability to resist the urge to consume psychoactive substances in high-risk situations. This study’s objective was to develop a cross-cultural adaptation of the eight-item version of the Drug-Taking Confidence Questionnaire (DTCQ-8) for all drugs except alcohol and to verify its content validity and reliability in a pre-test stage.MethodsThe following steps were taken: (1) implementation of the translation protocol and transcultural adaptation, (2) validation of the adapted content, and (3) assessment of reliability. Nine experts participated in the process of adaptation, and the trial’s sample comprised 40 drug users in treatment at a Psychosocial Care Center for Alcohol and Other Drugs (CAPSad).ResultsThe average indices of semantic agreement (0.989; 0.989; 1.00), idiomatic (0.967), experiential (0.956), conceptual (0.978) and content validity with respect to language clarity (0.972), practice relevance (0.958), theoretical relevance (0.958) and theoretical dimension (1.00) showed that the adaption was successful. The mean total score of the DTCQ-8 version for other drugs was 477.00 + 234.27-SD, and 57.5 % of the users were classified as having moderate self-efficacy to resist the urge to use drugs in high-risk situations. The Cronbach’s alpha coefficient was 0.889 for the complete instrument and 0.863–0.890 between items.ConclusionsThe DTCQ-8 version for other drugs proved to be easy to use and understand, and its process of adaptation was satisfactory for use in the Brazilian context. In this sample, the questionnaire was adequate to measure users’ self-efficacy to resist the urge to consume these substances in high-risk situations.