Several questions related to the demographic transition (DT) remain still open or need verification. E.g., it is unclear what factors are the decisive triggers of the DT. The present study addresses this issue by an innovative research approach. We focus on all populations which moved through the DT since 1950 and identify those which experienced the process at an exceptionally fast pace. We refer to these populations as “Express Transitioners” (ET). We use logistic regression models to analyze the determinants of express transitioning by comparing the ETs with the other DT countries. We find that urbanization appears to be the most relevant determinant of express transitioning. However, some results indicate that education might also be a relevant factor in some of the ET countries. Other variables show no significant influence. These findings provide new insights not only into the determinants of express transitioning, but also the general drivers of DT.