In this paper, we study overconfidence and goal-setting in academic performance, with and without monetary incentives. Students enrolled in a microeconomics course were offered the possibility of setting their own target grade before taking part in the final exam. They were also asked to guess their grade immediately after they had taken the exam ('post-diction'). In general, students overestimated their perfor- mance, both at the goal-setting and at the post-diction stages. Controlling for several sources of this bias (cognitive abilities, academic record and self-reported academic confidence), we find that the use of monetary rewards mitigates the overestimation of potential achievements and eliminates overestimation of actual achievements through the improvement of actual performance. Our results suggest that monetary incentives do not cause subjects to put more effort into correct guesses but make them put more effort into academic performance. Using students' academic records to measure overall skill, we find a strong Dunning-Kruger bias which is intensified in the presence of monetary rewards.