This article examines the professional integration of beginning teachers in French-speaking Belgium and the factors predicting an exit from the profession during the first years of their careers. The analysis of four successive cohorts of new teachers indicates that exit rates are very high during the first year but show a gradual decline afterwards. The exit rates are also much higher in secondary education than at pre-school and primary levels. According to the international literature, this research also shows that teachers with training in education are much more stable than their peers without teacher qualification. Concerning the work environment, the data indicate that the school's socio-economic level is not linked to the risk of leaving the profession. Finally, one of the main results of this study is the demonstration that over and above the influence of teachers' and schools' characteristics, a very close relationship is observed between job conditions over the first year in the profession and exit rates. These results argue for paying greater attention to the institutional conditions of career management in future research on teacher attrition and migration.