Research in the sociology of education argues that the educational system provides different learning opportunities for students with different socioeconomic backgrounds and that this circumstance makes the educational process an important institutional context for the reproduction of educational inequality. Using combined survey and register data for more than 56,000 students in 825 schools, this article conducts the first empirical test of the argument that instructional strategies which emphasize student responsibility and activity, also referred to as student-centered instruction, increase educational inequality. We analyze whether the impact of student-centered instructional strategies on academic achievement differs for students with different socioeconomic backgrounds. Results suggest that a student-centered instructional strategy has a negative impact on academic achievement in general, and for students with low parental education in particular. Our findings support the argument that the instructional strategy of schools is an important mechanism in generating educational inequality through the stratification of learning opportunities.