People with mental health and addictive disorders (MHADs) have higher rates of cigarette smoking, and less success in quitting smoking compared with the general population. Moreover, tobacco-related medical illness may be the leading cause of death in the MHAD population. We discuss the scope of this comorbidity, and approaches to the treatment of tobacco dependence in people with MHAD, including schizophrenia, mood disorders, anxiety disorders, and alcohol and substance use disorders. Finally, at the level of health systems, we emphasize the importance of integrated treatment of tobacco dependence in MHADs.