The aim of the present study is to explore changes both in approaches to learning as well as in students’ experiences of the teaching-learning environment and how these changes are related to each other during their Bachelor studies by using a longitudinal data set. The aim is further to explore how students’ approaches to learning and their perceptions of the teaching-learning environment relate to study success. Participants comprised of 103 students at the Faculty of Biological and Environmental Sciences who participated in the present study from the first to third year of their Bachelor degree studies. We used a modified version of the ETLQ questionnaire and conducted Confirmatory factor analyses on scales representing approaches to learning and the teaching-learning environment at both measurements. We investigated changes at the group level using a paired sample t-test and conducted the final analysis with regression analyses. We then used Structural Equation Modelling to analyse the relationship between approaches to learning, perceptions of the teaching-learning environment, and study success. The results showed an increase in the deep approach to learning and a decrease in students’ perceptions of teaching for understanding. Organised studying and interest in studies were related to study success. The results reveal the existence of complex relations between changes in approaches to learning and perceptions of the teaching-learning environment.