The rapid expansion of the knowledge society, due mainly to the ubiquity and access of information and communication technology (ICT), places a professional demand on teachers to acquire relevant knowledge to make use of technology in their classrooms. Thus, for teachers to effectively integrate ICT into their teaching repertoire, they must transform their pedagogical practices. In this regard, the quality of pre-service and in-service training is pivotal in preparing teachers for effective technology integration. Utilising a case study approach and Activity Theory principles as a theoretical lens, this study set out to explore the influence of ICT as a tool of instruction on the classroom practice of in-service teachers in Rwanda. Qualitative methods were employed to capture data through interviews, observations, and document analysis. Data was analysed using content analysis to understand in-service teachers’ constructions about learning through ICT and how it influenced their classroom practice. The investigation of the influence of ICT as an instructional tool to in-service teachers yielded unique patterns of their ICT learning-teaching experiences. The findings were two-fold. First, the ICT learning experiences of the in-service teachers changed their perspective towards teaching and learning with ICT in their own classrooms. Second, the teacher participants vicariously mirrored their lecturers’ use of ICT in their own classroom practice. This unintended experience created affordances for the in-service teacher trainees to not only learn ‘about’ ICT, but significantly ‘how to teach’ pedagogically with ICT. It is crucial for teacher trainees to experience the same type of learning environments they are expected to create in their own classrooms.