In the last two to three decades teachers' work has been plagued by problems internationally. These problems include a growing dissatisfaction of teachers about their working conditions (characterized by heavy workloads and low salaries), the growing attempts by governments to control teachers' work and the increasing negative public image of the teaching profession. This negative public image of teaching is manifested in the failure of the profession to attract enough students and the fact that those who are already in the profession want to leave. These factors had, inter alia, lead to a collapse of professionalism amongst teachers in general. There are, however, also other factors that have an influence on the professionalism of school teachers. It is argued in this article that the management role of the school principal is a crucial factor that influences teacher professionalism. This influence can be either positive or negative, depending to a large extent on how effectively the principal is managing the school. This article, derived from an empirical case study undertaken among a number of secondary schools in the Eastern Cape Province of South Africa, is an attempt to conceptualise the important and pivotal managerial role of the principal in promoting professionalism amongst teachers in this province.