The literature is considerably rich about engagement and academic achievement in the context of open and distance learning. However, there is limited research that investigates these variables with large scale participants. In this regard, the aim of this research was to investigate causal correlations between e-learning engagement time and academic achievement of open and distance learners according to course subject, dropout, and bounce rate variables. The participants of this study were 323,264 open and distance learners from Anadolu University, Turkey. Throughout this research, open and distance learners' engagement time levels and their academic achievements are compared. Academic achievement was found to increase significantly when learners engaged more with e-learning materials.