Doctoral completion rates are an indicator of successful doctoral programmes and of a region’s potential of highly skilled workforce. The Human Resources in Research – Flanders (HRRF) database contains data of all academic staff appointments, doctoral student registrations, and doctoral degrees of all Flemish universities from 1990 onwards. Previous research has identified the following factors as affecting successfully completing the PhD: cohort, scientific discipline, type of scholarship or appointment, gender, age, and nationality. We present a competing risk analysis of factors determining PhD completion and drop-out. This event history technique allows for determining the relative impact of each of these characteristics on the level of success/failure and time to degree. It predicts at what time periods the ‘time to degree’ and ‘time till drop out’ is most likely to occur, and why some individuals experience the event earlier than others. Our results show that scientific discipline and funding situation are the most important factors predicting success in obtaining the doctorate degree.