Background: Self-regulated learning (SRL) encompasses the strategies and behaviours that allow students to transform cognitive abilities into task-specific academic skills. Research in higher education has found a relationship between SRL and academic outcomes. However, whether SRL improves as students gain educational experience in undergraduate science has not been adequately studied. It is also unclear whether traditionally strong predictors of academic performance, such as the Australian Tertiary Admissions Rank (ATAR), and science background, remain strong in the later stages of a science degree. Purpose: The purpose of this study was to investigate whether SRL changes over time in undergraduate science, and whether SRL, the ATAR, or a student's science background predicted their academic performance. Sample: The sample comprised a cohort of agricultural science students (n = 213) from a large Australian University followed longitudinally from 2018 to 2020. Design and methods: Students completed a questionnaire to assess SRL in their first and third years of undergraduate study. They also completed a knowledge survey at the start of first year to assess confidence in scientific material. Analyses revealed that students' SRL increased over the degree, but not over a single semester of first year. Additionally, it was found that students' average semester marks were related to knowledge survey scores, and with students' ATARs, but not with their SRL. Conclusion: These results indicate that the academic aptitudes that contribute to academic success in high school continue to be advantageous through to the end of undergraduate study, but also suggest that students' initial scientific confidence may be particularly important to long-term university success.