SIGNIFICANCE: Persons with intellectual disabilities, like all people, need regular physical activity to maintain a healthy lifestyle. However their participation often is dependent upon support from parents. Therefore, this study was conducted to assess the influence of parents on physical activity participation by their children with intellectual disability. The research design was based upon the Kimiecik et al. (1996) family influence model. Hypothesized correlates included both parent factors (age, values, concerns, physical activity) and child factors (disability, severity, BMI). DESIGN: Participants were 193 parents of school-aged and adult children with intellectual disabilities who were spectators at a Special Olympics event. Mean parent age was 48.14 years (SD=9.21), with mothers constituting 83% of the sample. Parents completed the Physical Activity Values and Concerns Survey, which incorporated a parent 7-day recall of children's physical activity from the Amherst Health and Physical Activity Study (Sallis, 2002), a parent 7-day recall of parent's physical activity from the San Diego Health and Exercise Survey (Sallis, 1989), and items on parent values and concerns about their children's physical activity derived from the research literature. The survey return rate was 74%. RESULTS: Multiple regression revealed three variables that help to predict physical activity participation by persons with intellectual disability: children's physical activity = 1204.88 intercept + .53 parents' physical activity – 17.81 severity of child's disability – 10.93 parents' age. This equation was interpreted in terms of difficulty finding appropriate opportunities for physical activity participation for persons with more severe disability, as well as difficulties experienced by aging parents in supporting an active lifestyle for their children with intellectual disability. Although parent values and concerns did not add to the regression equation, it was interesting to note that this sample of parents assigned high ratings to the importance of physical activity for their children. With items rated on a 4-point Likert scale where 1=not important and 4=extremely important, average parent ratings were 3.62 fun, 3.52 psychosocial benefits, 3.36 health-related physical fitness, 3.29 skills, and 3.08 winning. Most parents did not perceive significant barriers to participation. With items rated on a 3-point scale where 1=not a concern and 3=prevents participation, parent ratings were 1.56 nature of the program, 1.49 staffing, 1.43 availability/accessibility, 1.35 convenience, and 1.27 family resources. The findings about parent values and concerns were attributed in part to a biased sample of parents whose children already are physically active. Additional research is planned to study other parent populations.Keyword(s): adapted physical activity, physical activity, research