investigates whether students from lower socio-economic backgrounds have a higher rate of university drop-out as compared to their wealthier counterparts, once one allows for their differential prior achievement. Using a combination of school and university administrative data sets, we show that there is indeed a sizeable and statistically significant gap in the rate of withdrawal after the first year of university between the most advantaged and disadvantaged English students. This socioeconomic gap in university drop-out remains even after allowing for their personal characteristics, prior achievement in secondary school and university characteristics. In the English context at least, this implies that retention in university of disadvantaged students is arguably a more important policy issue than barriers to entry for these students.