Previous research on the gender gap in mathematics indicates that, in the case of Spain, the gap is stable and has even increased during the last years both in primary and secondary education. The objective of this paper is to analyze whether this gender gap remains by changing the academic level and the way of measuring performance. A sample of 2,713 undergraduate management students (1,478 female and 1,235 male) has been analyzed. The results show that the mathematical level in university entrance is significantly higher in male students, confirming the existence of the aforementioned gap. Nevertheless, throughout the first year of university studies, it has been observed that in most degrees there are no differences between male and female students in terms of their achievement in mathematics. In fact, in those cases in which differences do exist, they occur in the opposite direction, with female students achieving better performance.