We investigate the aspects related with students segregation between the higher education provided by the public sector and that one which is offered by the private sector. Based on data from the National Household Sample Survey (PNAD/IBGE), we find evidence that an extra year on student's mother education affects positively the likelihood of students joining a public college (by the amount of 0.3 percentage point). Using the method of Oaxaca-Blinder Decomposition for the score on the National Secondary Education Exam (Enem) of the first-year students, we find that only one third of the difference of -0.61 points between students from private and the public sector can be explained by the observable variables, while two-thirds of the difference would be associated with unobservable variables, such as the student’s ability. Thus, Enem’s score, net of the others observable variables, would represent the intrinsic characteristics of the student, including ability. If one uses the Enem's net score as an explanatory variable in the decomposition of score of National Student Performance Exam (Enade) of the undergraduate students, the result is that more than 90% of the gap between sectors could be explained by the observable variables, while the Enem’s score is the main determinant for explaining the score gap.