In this paper, we consider the effect of working while in school on the probability of dropping out at the secondary level. The difference between this version and an earlier version of this question discussed in Dagenais et al (1998), Travail pendant les études et abandon scolaire : causes, conséquences et politiques d'intervention is to treat grades obtained in school at the secondary level as an endogenous variable. This more general econometric specification confirms our previous results in identyfing several determinants of dropping out and different policies which can be put into action by the governments in order to reduce dropout.