The present case study explored the teaching belief systems of pre-service science teachers (PSTs), including epistemological beliefs, self-efficacy beliefs, conceptions of science learning and teaching and pedagogical content knowledge. Based on their epistemological scores, three PSTs who were categorised as exhibiting naïve, moderately sophisticated and sophisticated beliefs were selected for analysis. Each of the participants was interviewed individually on four occasions and prepared a lesson plan. Analyses of interview transcripts and lesson plans indicated that PSTs' epistemological beliefs were differentially related to particular domains and topics and that their previous learning experiences and observations were more likely to influence their teaching behaviours. The conclusion section presents suggestions for implementing study findings and recommendations for future research.