This study explored the teacher knowledge manifestation of Integrated Science (IS) teachers who have specialised in Chemistry, Biology or Physics during their pre-service teacher education. 60 experienced Integrated Science teachers responded to an 'Integrated Science Teacher Knowledge' questionnaire which embraced different dimensions of teacher knowledge. The results of the study indicate that the IS teachers have a common set of knowledge, skills, and dispositions that are, in their professional opinion, needed and in some instances, would enable them to teach IS. The research participants had considerable knowledge as well as clear views about what it meant for them to be IS teachers. It however should be noted that there was a marked variance in the perception of the three cohorts of teachers towards teaching through Practical Work, importance of pre-service teacher education specialisation towards teaching IS and knowledge of students' culture. This study provides contextual inputs to effective IS teacher education re-alignment informed by the IS teacher practitioners, those with the craft knowledge of the contextual environment of the IS classrooms.