One of the most noticeable changes to the university student profile over the last decade is the increasing number of mature-age students. This study examined the relationship between previous academic performance, psychological characteristics of the student, learning strategies, and the first year academic performance of school leavers and mature-age students through structural equation modelling (SEM). A total of 1193 first year university students completed a questionnaire at the beginning of their first year of study, and provided consent for their academic results to be tracked over their first year at university. While the overall model of success appeared to fit for both groups, differences were identified in the order of importance of constructs affecting achievement and the strength of some relationships. The most obvious difference occurred in the relationship between previous academic performance, self-reported learning strategies, and achievement in first semester, with previous performance a more accurate predictor of school leavers' performance and self-reported learning strategies a more accurate predictor of mature-age students' performance. This study has implications for the university in terms of the targeting of academic support services for students of different ages.