Informed by a socio-cultural perspective, this study investigated how two student teachers developed their CT-oriented pedagogies in a pre-service language teacher education program in Hong Kong. Drawing on multiple sources of data including semi-structured interviews, relevant documents, and informal communication, the findings revealed the participants’ growing pedagogical knowledge and competence in CT teaching, influenced by various forms of mediation – i.e., object-regulated, other-regulated, and self-regulated – afforded in the situated context. The gap between the curriculum's goal and its implementation was identified as a crucial factor that impeded their learning to teach CT in the program. The paper concludes with practical implications that can help integrate CT into pre-service teacher education programs with a view to preparing future teachers with a high level of CT and CT-focused pedagogies.