Regular physical activity is vital for adult individuals with intellectual disabilities. The purpose of this review was to assess critically the evidence on effectiveness of physical activity interventions for adults with intellectual disability. An electronic database search was conducted. Research was then assessed for methodological rigor, and strength of the evidence was determined. Eleven clinical studies met inclusion criteria. Interventions studied included a variety of physical activity modes. Critical review revealed moderate to strong evidence that physical activity positively affected balance, muscle strength, and quality of life in individuals with intellectual disability. The authors also found that the research in this area needs to be translated into practice, specifically the development of physical activity programs that are adaptable to the needs of individuals with intellectual disability.