In the current university context, numerous students meet difficulties with their career guidance. In order to support the active elaboration of their project of career, an approach seems to be relevant, the portfolio, collection of tracks and reflections built by the subject himself. Two cases of implementation of portfolios in the university pedagogy are presented, one within the framework of French DUT diploma, the other within the framework of a professional master. Despite the differences of context and purposes, these portfolios allow the students to build the expected approach and they support instrumental geneses.