Abstract It is increasingly recognized that families and communities are important in helping youths develop the knowledge and skills they need to obtain technologically sophisticated jobs, which are an emerging part of the global economy. In this paper we adopt social capital as a framework for examining the influence of family and community on promoting educational achievement among public school students. We explore more fully the role of community social capital in influencing educational performance beyond that attributed to family social capital. Using data from the National Education Longitudinal Survey (NELS), we find that both process and structural attributes of family social capital are key factors affecting high school students' educational achievement. Process and structural attributes of community social capital also help youths to excel, though they contribute less strongly to achievement. These findings suggest that policies designed to promote educational achievement must extend beyond the school and must seek to strengthen social capital in the family and the community.