This study examines by means of quantitative and qualitative data analyses which factors determine the choice for more masculine or more feminine fields of study by male and female bachelor students. The quantitative analyses are based on data of 4758 bachelor students, of which 1808 males and 2950 females, taken from STUBARO 2011-2012, a yearly online survey of students of Ghent University. The qualitative data are data of 15 female and 8 male students in gender-atypical fields, gathered by means of in-depth interviews and focus groups. Family background only slightly explained the gendered choices. More important were the students’ occupational values, as more feminine values decreased the likelihood of being in more masculine fields of study, and vice versa. Previous educational careers appeared to be most important, namely mathematics, which determined the enrolment in masculine fields somewhat more for men than for women.