Recent research literature on learning to teach has several important strands: the role of subject matter; the extent to which pedagogical knowledge and procedural routines are significant; concepts of learning and teaching; and the role of reflection in learning to teach. The present study adds both to the debate on the links between subject knowledge and pedagogy, and to the case law on learning to teach. A two-year longitudinal comparative case study was carried out on four postgraduate student-teachers. Data sets included: biographical data; details of course content and structure; diaries kept by the students on courses and teaching experiences; tests at entry to the course and exit on subject knowledge in maths, science, music and English; tests on iesson planning (pedagogical content knowledge); questionnaires on beliefs about teaching; lesson observation transcripts and notes on the two teaching practices; prelesson planning questionnaires; post-lesson interviews and general interviews with students and staff; and similar lesson observation and interview data for the first year of teaching. The student-teachers were selected on the basis of a number of criteria, including specialism within the course of maths, music or science; performance in subject knowledge tests; participation in the follow-up study during the first year of teaching; the quantity and quality of diary evidence foreach student; and the initial assessment of lesson quality made by the trained observers. A major part of the research involved the analysis of discourse in lessons for evidence of subject matter knowledge and teaching competences. This part of the analysis was underpinned by theoretical models of teacher knowledge and teaching competence. From these detailed analyses a fine-grained evaluation was made of a sample of each student-teacher's lessons. The case studies were written so as to present data chronologically and from a number of different viewpoints.The analysis of the various data sets and comparison of the sample students has revealed patterns about the relationship of subject knowledge and teaching performance. These have implications for teacher education, especially for the relationship between university-based training and schoolbased work.