This study investigated the contributions of maternal education and ethnicity to three dimensions of home-based parental involvement in young children's education and development: parental expectations about educational attainment, children's activities at home and outside the home, and family routines. Controlling for family background variables such as family size and structure, household income, and neighbourhood safety, we examined these relations in a nationally representative U.S. sample of 9,864 Asian American, African American, Latino American, and European American five-year-old children. Multiple regression models suggested that maternal education explained small to moderate amounts of variation in parental home-based involvement, and was more strongly associated with these outcome variables than was income. Ethnicity significantly predicted additional variation in only two outcome variables: parental educational expectations and family discussions. Maternal education plays a unique role in explaining U.S. ethnic group variations in parental involvement in young children's education. (Contains 1 figure and 4 tables.)