ABSTRACT Educational reform efforts and contemporary research have consistently called for enhancing young people’s interest in STEM study and career choices. In response to this challenge, we utilise and extend Social Cognitive Career Theory to examine the development of secondary school students’ self-views in relation to science and STEM career aspirations over a period of 5 years. Data were collected through semi-structured individual interviews at eight different times and analysed using content analysis. The findings showcase dynamic relationships between students’ self-views and career aspirations, influenced by opportunities for science engagement, the social context and family-related factors. Family backgrounds and expectations, innate resources, gender differences, science-related experiences associated with context and time were found to have a critical role. The findings speak to the need for future longitudinal research, from secondary school to career paths. Such research can enhance our understanding of the developing relationship between self-views and career aspirations, potentially facilitating stronger identification with science and relevant career aspirations, benefiting curriculum design.