Résumé : A central trend in qualitative studies investigating doctoral students’ dropout is tostress the importance of students’ integration and socialisation in their working environment.Yet, few of these studies actually compared the experiences of doctoral students who completedor quit their PhD. In order to overcome this limitation and identify the factors thatdifferentiate these two groups, the present study interviewed 21 former doctoral students: 8completers and 13 non-completers. The results show that what best differentiates these twogroups of participants is the extent to which they feel that they are moving forward, withoutexperiencing too much distress, on a research project that makes sense to them. We assumethat this set of factors is central in the dropout process. Support from doctoral peers was foundto play a positive role overall but did not contribute to differentiating the two groups,presumably because peers have a limited impact on dissertation progress. Supervisors’supportwas central to the participants’ stories; it is thus assumed to play a role in the process, but thisrole is complex and needs further investigation. These results call for a stronger considerationof the doctoral task itself when investigating the process of persistence and attrition and for amore integrated framework that considers jointly both task- and environment-related aspects