This chapter overviews the current literature on substance use after disasters in affected populations. Several studies examined different aspects of substance use, such as prevalence, comorbidity, correlates and/or predictors of alcohol, tobacco and drugs use. The chapter outlines the prevalence of substance dependency-abuse, changes in substance use, and associations between substance use and posttraumatic stress disorder (PTSD) or other mental health problems after different categories of disasters. It describes the associations between substance use and mental health disturbances after several types of disasters. The chapter presents correlates of substance use or misuse in detail, that is, (independent) predictors of substance use, as well as substance use as a (independent) predictor for PTSD and other postdisaster mental health disturbances. It focuses on residents affected by natural and technological disasters as well as disasters caused by mass violence and terrorism.