In Chile many university students do not persist to graduation. Some students dropped out in the first year, others later. The objective of this study, based on students admitted to but not graduating from selective universities, was to identify factors associated with their academic success and length of persistence before withdrawal. The 707 subjects for the study were a non-probabilistic sample of two cohorts of students who had withdrawn from 11 selective universities before graduation. One cohort of students had been admitted in 2010. The second cohort for this study was composed of students entering in 2016 and 2017. Data was collected in 2021 from university records and a questionnaire survey of the students. Pre-university measures included family education and income, secondary level academic performance, and cognitive knowledge. In-university measures included academic performance, and scales representing academic resources, family stability, non-student work, and engagement in social and academic activities. Data were analysed using correlations, means tests and linear regression. Pre-university (family and secondary school) factors influenced academic success in the first year of enrolment but not in later years. Academic success in the first year of university had the highest overall association with persistence. After Year 1 other factors contributed.