In this study, children's participation (N = 1,420) in activities outside of elementary school was examined as a function of disparities in family income using data from the Panel Study of Income Dynamics, Child Development Supplement. Children's neighborhood and home environments were investigated as mechanisms linking income disparities and participation rates. Family income was positively associated with children's participation in activities, with the largest effect sizes evident for children at the lowest end of the income distribution. Affluence in the neighborhood and cognitive stimulation in the home were both important mediators of the association between income and participation, explaining from approximately one tenth to one half of the estimated associations between income and participation. (Contains 12 footnotes, 7 tables, and 1 figure.)