Abstract : This research on the grade retention to the CP erects a detailed inventory of the knowledge on this question which gives rise to the more of animated discussions between the researchers and the teachers, and this since a long time. By allying the historic, comparative, economical and educational approaches, she conveys principal empirical results attached to the many facets of this measure that is more than an educational done. The empirical contribution of this study is based on a longitudinal followed during two years about more than three thousand students on CP in public schools of the French department of the Côte d'Or. We highlight that the grade retention are received favourably by the teaching, the students and their families, in particular when it is proposed in the end of the first year of primary school. Nevertheless, conducted discussions with the students repeating a year, their nearest and dearest show that this experience isn't neuter and a negative statute exists. This additional year in his young pupil's life doesn't bring the anticipated benefits for the school's acquisitions.