Substance use disorders are among the most frequent psychiatric disorders found in suicides. In psychological autopsy studies between 19% and 63% of all suicides suffered from substance use disorders, mostly from alcohol use disorders. Suicide risk is highly increased in substance use disorders, particularly in alcohol use disorders, and in co-morbid alcoholism and depression. So far, some risk factors for suicide have been identified in alcoholism. Nevertheless, various questions about the relationship between substance use disorders and suicide remain open, which indicate directions for future research.