Greater understanding can increase our knowledge and intervention effectiveness for activity participation problems of children with disabilities. We examined participation difficulties of children with autism spectrum disorders (ASD) and intellectual disabilities (ID) in the 2011 Survey of Pathway to Diagnosis and Services. We utilized propensity score matching with inverse probability of treatment weight with questions from parents of 1783 children aged 6-17 years. Friendship was the most difficult area for all children. Children with both ASD and ID experienced the most difficulty in all areas, followed by ASD alone. Reported levels of home life, friendships, classroom and leisure difficulties were moderately correlated for all children. Children who were previously diagnosed, but have no current diagnosis experienced substantial difficulties.