This article reviews research conducted on the cigarette, alcohol, and illicit drug use of adolescents and adults with mental retardation (MR). The majority of the research related to substance use conducted on this population has been limited to surveys. Overall, results of these studies suggest that, although substance use is slightly lower among those with MR than among nondisabled comparison groups, it is nonetheless a problem for many individuals. This research is reviewed and a discussion of both the general and specific flaws of these studies follows. Further, the examination of education, prevention, and treatment programs for this population has been overlooked, indicating that individuals with MR are likely not receiving the services most appropriate for them. The article concludes with a discussion of several topics that need to be addressed in future studies, including research on potential best practices in the overlooked areas of substance abuse interventions.