It is important to enhance pre-service science teachers' pedagogical content knowledge (PCK) during teacher education programs. As an alternative, this research aims to investigate whether participating in a lesson study enriched with content representation contributes to pre-service science teachers' PCK improvement in the heat and temperature topic. Three pre-service science teachers participated in the study. The study can be localized under the instrumental case study approach. Semi-structured interviews, content representations, observations, and field notes were used as sources of data collection. Results assert that participants' science teaching orientations did not change a lot, participants improved in terms of knowledge of curriculum and knowledge of learner components of PCK, and participants improved in terms of knowledge of instructional strategies and knowledge of assessment components of PCK excluding subject-specific strategies dimension of the former, and what and why to assess dimensions of the latter. This study has several implications for teacher educators and science education research.