Cultures and ethnic groups within cultures prescribe, proscribe, or tolerate use of various psychoactive substances for social or personal purposes. In the United States, these ethnic strictures and practices vary widely. Ethnic enculturation into particular psychoactive substances can either reduce the risk of substance abuse or greatly increase this risk. To function effectively in a multiethnic society, psychiatric physicians of North America should learn to assess the cultural and ethnic dimensions and effects of substance abuse among their patients. In addition, they should be culturally sensitive to those aspects of treatment that can impede or augment successful outcomes. Finally, any and all attempts at primary prevention, early recognition and intervention, and rehabilitation should reflect the complex cultural, political, economic, and religious factors that influence substance use and abuse.