A review of research on drug use among immigrant populations notes several theoretical approaches available to address the relevance of immigrant population experiences to drug use. The acculturative stress model suggests that cultural conflict at point of destination and lack of social and economic resources for coping may result in migrant substance use as a maladaptive coping mechanism (Berry et al., 1987; Cheung, 1990-91; Mirdal, 1984). In contrast, an assimilation (or acculturation) model suggests that as immigrants adopt the customs and practices of the host society, their patterns of substance use will also begin to parallel those of their new environment. Linear models of stress adaptation and acculturation have been challenged by other researchers who have suggested that bicultural immigrants, that is, those who are able to adapt to their new social environment while retaining important elements of their native culture, are less likely to develop substance use habits (Tucker, 1985). In addition to the problems that confront most immigrants in their new environment, refugees often must face the added burden of coming to terms with the circumstances that forced their relocation. A related issue is the timing of onset of substance use and misuse among refugee populations. Compared to research among immigrant and refugee groups, more attention has been paid to the epidemiology of substance use and misuse among homeless persons. Although the misuse of alcohol and, more recently, illicit drugs and prescribed medications have come to be recognized as a serious problem among many homeless persons, the nature of the relationship is not well understood and remains controversial. Social selection and social adaptation processes represent two competing models of the relationship between substance misuse and homelessness. The exploration of methods for making treatment and other needed services available to displaced populations in ways, times, and places that engage and maintain their use should be considered. The limited information regarding health care use among immigrants and refugees suggests that they are less likely to take advantage of available services for a variety of cultural, economic, and legal reasons. A 33-item annotated bibliography and 51 references