This presentation reports on a longitudinal research project, which follows students from initial teacher education into their first teaching jobs. The aim of the research is to provide insights into how student teachers become novice teachers of mathematics and science. This presentation reflects on work in progress and reports the second part of the study, that is, novice teachers opportunities and difficulties in incorporating their beliefs and conceptions about mathematics and science education into their school practice. The first part of this longitudinal study focused on student teachers' beliefs and conceptions about mathematics and science, for mathematics, drawing on work of mathematics educators such as Alba Thompson, Thomas Carpenter, James Hiebert and Elisabeth Fennema, and for science, drawing on the work of Svein Sjoberg, Peter Hewson and Leif Ostman. The first part formed the background to this second part of the research, which highlights how new teachers implement their ideas about mathematics and science education. This presentation draws on Bernstein's theory of educational codes to analyze and understand the school context in which the novice teachers work. The novice teachers' act of teaching is, among other aspects, dependent on their beliefs and conceptions of mathematics and science teaching and on the educational code used in their school. The forms of data collection used for this part of the study included observations, field-notes, post-observation interviews and reflection on earlier interviews at the end of initial teacher education. The interviews were analyzed using Bernstein's concept of classification and framing. The result suggests that teachers have images not only of mathematics and science, but also of what it means to know and learn mathematics and science. These subjects and ways of knowing are compared to the Swedish curriculum, which underpin the idea that pupils construct their own learning. Half of the new teachers seem to have internalized this view on learning. Another aspect of the study is how the teaching of science and mathematics can enhance critical citizenship, empowerment and democracy. The novice teachers have not, it seemed, been able to develop this aspect so far in their teaching practice and in fact, only a few mentioned this as an aspect of their work. Moreover, findings from the research indicate that novice teachers do not feel confident about their teaching after two years working in school. The school context differs in their relation to their use of collection or integrated codes with schools offering different opportunities for teachers to develop and improve teaching. The outcome of this part of the study is that schools need to develop better ways of supporting new teachers and of encouraging experienced teachers to teach more critically.