The Treatment‐systems Research on European Addiction Treatment study (TREAT‐project) is a longitudinal multicenter study on predominantly opioid‐dependent patients and their health‐care system in six European cities. As part of the examination of the drug services, this study evaluates level of burnout, coping strategies, perceived self‐efficacy and job satisfaction among health‐care workers treating opioid addicts. Employees were recruited from organizations in Athens, London, Padua, Stockholm, Zurich and Essen. The Maslach burnout inventory, Brief COPE, general self‐efficacy questionnaire and a job satisfaction scale were filled in by about 383 drug service workers. One‐third of the staff suffer from severe burnout. London and Stockholm colleagues are significantly more burdened than Zurich personnel where job satisfaction is highest. No cross‐national differences could be detected concerning coping styles or level of perceived self‐efficacy. Burnout is positively correlated to passive coping strategies and negatively linked to self‐efficacy and job satisfaction. Males experience more depersonalization. Organizational features such as the entry‐threshold level of the institution or out‐ vs. inpatient setting are relevant for coping strategies and job satisfaction. These and other findings are discussed in relation to preliminary data from the TREAT‐project on characteristics of opioid addicted patients and other specific features of the drug treatment system. Copyright © 2009 John Wiley & Sons, Ltd.