The purpose of this study was to investigate whether parental involvement (PI) activities out of school varied with family background in the United States and whether PI mediates the relation between family background and student achievement. This study was grounded within Bourdieu's cultural capital theory (YEAR). Data were collected in 2007 using the Parent and Family Involvement (PFI) survey as part of the National Household Education Surveys (NHES). The results showed that parent education level and household income had significant positive relation with PI activities out of school, which in turn was a significant predictor for student achievement, p < 0.05. Moreover, White parents were significantly less involved in activities out of school with their children than did non-white parents. The bootstrapped indirect effect of PI out of school was significant for both parent education and household income in predicting student achievement, p < 0.05. We concluded that education inequality existed given the relation of family background to student achievement.