In this article, the determinants of "time to dropout" from doctoral studies and "time to PhD completion" are studied using a discrete-time competing risks survival analysis for a sample of 3092 doctoral candidates from the Université libre de Bruxelles. Not surprisingly, results show that students supported with research fellowships have much higher PhD completion hazards than teaching assistants or unfinanced students. Concerning dropout, students with no financing showed the highest withdrawal rate, while students with selective research fellowships showed the lowest one. Dropout is also influenced by the ability of the student, which is correlated to their success in the fellowship allocation procedure. However, the type of financial support influences time to dropout from doctoral studies even when controlling for the ability of the student. Finally, our findings suggest that there are no significant differences in dropout and degree completion between fields of study, except for unfinanced students.