Student employment is usually thought to curb academic achievement. Our research relating to a survey at a French university in 2012 aims to assess the effects of the employment characteristics and, specifically, the student working hours. Using a statistical model which take into account the probability to find a job during the study, we show a negative effect of student wage-earning employment, particularly for young people working more than 8 hours a week. The type of employment also affects the chances of success: students with public sector jobs and those which have the possibility to arrange their schedule appear to be less prone to failure.