Willingness to compete has been found to predict individual and gender differences in educational choices and labor market outcomes. We provide further evidence for this relationship by linking Swiss students' Baccalaureate school (high school) specialization choices to an experimental measure of willingness to compete. Boys are more likely to specialize in math in Baccalaureate school. In line with previous findings, competitive students are more likely to choose a math specialization. Boys are more likely to opt for competition than girls and this gender difference in competitiveness could partially explain why girls are less likely to choose a math-intensive specialization.