From the perspective of the Vygotsky’s Socio-cultural Theory, this qualitative study aims to explore the reasons behind the dropout rates among distance-learning students at a university in the Mekong Delta region, Vietnam. Data was collected through in-depth semi-structured interviews with five former students from the English Language Bachelor’s Distance Education Program at the University, one program manager and two teachers. The results reveal that dropout among distance-learning English language students is due to both internal factors within the learners and external factors.