This article examines the level of social commitment of the low-educated in the Netherlands, and answers the following research questions: To what extent do low- and high- educated people differ in their level of social commitment, to what extent does the difference become larger across birth cohorts and over the life-course, and how can it be explained? Five indicators of social commitment, which were retrospectively asked for the ages of 20, 30, 40, 50, and 60, are used: electoral participation, political interest, newspaper reading, voluntary work for local organizations, and membership of societal organizations. Multilevel analyses for repeated measurements show that low-educated people are considerably less committed socially than high-educated individuals. Trends towards social marginalization are observed across birth cohorts, particularly with regard to political behavior and attitudes, where the gap between the low- and high-educated widens. A divergence in political interest is also observed during the life-course. These differences between the low- and high-educated are largely attributable to differences in human capital, labor market success, and partner’s resources. The social background of the low-educated is a less important factor.