This article studies the short-run effect of increased student involvement on academic achievement, motivation, and grade repetition. We use a randomized field experiment among 130 tenth-grade students in a Dutch upper secondary school. Students who are more involved in their own learning process have significantly higher academic performance and a lower chance of grade repetition. Extrinsic motivation was lower for these students, but there was no effect on intrinsic motivation. All effects can be attributed to male students. The main explanation for the findings is that students feel more responsible and in charge of their own learning process.