Résumé : The present study aimed at (1) identifying the naturally occurring patterns of motivation among doctoral students and (2) assessing their impact on the doc- toral completion process.Grounded in the self-determination theory, the paper investigated needs satis- faction and the doctoral completion process.Two complementary methods were used. First, k-mean clustering was used to classify 461 doctoral students according to their feelings of competence, auton- omy and relatedness. Second, the completion process of these five profiles was investigated through multi-group path analyses.This paper provided a motivational perspective on doctoral completion process that highlighted significant individual differences.