Developing science identity in pre-service science teachers is important as it influences their perceptions about science teaching and learning. Pre-service teachers' science identity can be developed in their specific modules where they obtain content knowledge. Grounded in the notion of pre-service teachers' learning agendas, and identity development, this paper presents an argument pertaining to how science content modules at one South African university contribute to pre-service teachers' development of their identities as science teachers. Data were collected through individual interviews with 13 pre-service science teachers and analyzed using an inductive thematic analysis. The findings revealed four categories of aspects that influenced the pre-service science teachers' identity construction and development. The first is about the nature of the subject matter knowledge taught in the modules. The second is about the context in which this subject matter knowledge is taught. The third concerns how teaching is conducted, and the last comprises the nature of practical work. These findings are discussed, and the implications related to the structure of science content modules in initial science teacher education programs are discussed.