Undergraduate university enrolment in Canada is characterized by a higher proportion of women to men, with a pattern of gender segregation across some disciplines. Within some disciplines, there is also a pattern of internal sex segregation whereby women and men still sort themselves into gendered sub-fields, a pattern that is particularly evident in undergraduate business management programs. This study set out to understand why this segregation occurs. The study found that men and women use the same criteria in selecting a business major, including beliefs about success and fit, as well as advice from referent others. However, they attach different weight to these factors in a pattern that is gendered. (Contains 11 tables and 1 note.)