This thesis aims to identify the factors that cause school evasion in higher education, focused specifically on Mathematics, Physics and Chemistry undergraduate courses of the Universidade Federal Fluminense in 2009. The university characterises student evasion in 09 (nine) categories. This study proposes to investigate the school evasion by courses abandonment. To contextualize this research was recovered the understanding about the history of higher education in Brazil and Student Assistance in Higher Education, furthermore some reflections were done about the social role of the university and the issues that cross the school evasion problems in higher education. To develop this work were used quantitative and qualitative data. The data capture was performed through semi-structured interviews based on a predetermined route with 12(twelve) ex-students, distributed as follows: 06 (six) Mathematics, 03 (three) and Chemistry 03 (three) physics. In the last recent decades there has been a significant increase of vacancies for higher education which allowed more access to students at public and private universities, however, there was also an increase of students who for various reasons, could not complete their courses. Based on this situation, this study sought to identify the factors that stimulated the students interviewed to leave their courses and was designed this student profile considering its current socioeconomic and educational situation. Also, this work identified the participation degree of the students that left their courses in programs of scholarships or student assistance in order to promote their permanency in the university.