The main purpose of this study is to investigate a science teacher's beliefs and understanding of the nature of science (NOS) in order to be able to relate these beliefs about the NOS to classroom practice and therefore student experience. Teachers' beliefs about the NOS are embedded in their experiences of learning and teaching science and hence, this research contains elements of a life history approach within a qualitative interpretive design. A single science teacher, Ikraam (a pseudonym), working in a community-based co-education school in one of the socio-economically disadvantaged areas in Karachi, was the focus of the research. His life story plays a vital role in this study to illustrate his views of the NOS. The data includes six life history interviews, two group interviews with his students, eight classroom observations and document analysis. The study revealed that the teacher's beliefs about the NOS were embedded in his own experiences of learning and learning to teach and indicates that in some cases Ikraam held informed conceptions about the NOS but in some important areas he displayed naive views.