To date, very little published information has been available on the physical activity participation of disabled youth. A questionnaire, which was modified from the Canada Fitness Survey, was distributed by mail to physically disabled, sensory impaired, and chronically ill children and adolescents in Ontario, Canada. Nine hundred eighty-seven responses were collected from subjects 6 to 20 years of age, with a response rate of 58%. Twenty-nine percent of physically challenged youth were found to be sedentary, and 39% were active. Activity levels were significantly related to age (p < .01), with a marked decline in the second decade of life. Activity levels were not significantly influenced by gender, but the data suggest that girls have lower activity levels and a faster and earlier decline in activity than boys. Overall, the data collected provide baseline information on the role of physical activity in the lives of Ontario youth with physical disabilities, sensory impairments, and chronic illnesses.