What is it that we need to know to understand teachers and teaching in high schools today? In 1988 the Center for Research on the Context ofSecondary School Teaching, the larger project sponsoring this study, held its first meeting with the teachers who had agreed to sit on an advisory board and to help a team of researchers address that question. In that informal conversation the topic of departments appeared and reappeared with remarkable frequency, for while the subject department may have been 'strangely ignored' from the perspectives of educational researchers, when teachers themselves portray the world of the high school the subject department is a highly visible feature. It appears prominently in their depictions of what matters to teaching, both as subject - it is what they teach - and as organizational setting - it is where and with whom that teaching takes place.