An innovative school science curriculum in South Africa requires the inclusion of African societal/cultural knowledge, such as indigenous knowledge (IK). The main project involves introducing argumentation to accomplish this requirement. We used a focus group plus critical incident technique to ascertain nine teachers' understandings of argumentation and IK, their perceptions of how argumentation helps in teaching IK, examples of how argumentation-teaching had (or had not) worked in their classrooms, and their suggestions. Our results show that the teachers accepted argumentation as a viable approach to teach science and introduce IK into their classrooms.