This paper reports the results of a large randomized field experiment that investigates the extent to which nudges can stimulate student participation in teaching evaluations. Three different nudges were tested: (1) heightening students? perceived impact of teaching evaluations, (2) communicating a descriptive norm of high participation, and (3) using the commitment-consistency principle by asking students to commit to participation. We find that none of the nudges was effective: all treatment effects were insignificant and close to zero in magnitude. Exploring heterogeneous treatment effects, we find evidence that the effectiveness of the commitment treatment differed across students: it increased participation among students with good average grades, whereas it decreased participation for students whose grades were poor. Overall, our results add to the body of evidence that demonstrates that nudges may not always be as effective as suggested in the literature.