This article analyses the concept of organizational culture and the relationship between the organizational culture and the performance of staff work groups in schools. The article draws upon a study of 12 schools in Wales, UK, which despite being in disadvantaged settings have high levels of pupil attainment. A model is developed linking the organizational culture of the staff group to performance as measured by pupil attainment using the conceptual analysis and the interpretation of the research findings. In the model, organizational culture, as a root metaphor, is defined by the organizing metaphors 'productive', 'strong' and 'highly inclusive'. The absence of substantial subcultures, the head teacher's leadership and reflective practice are important influences on the overall organizational culture and play a part in linking organizational culture and performance. In the model, the organizational culture underpins practices that bear directly on the primary task which is in itself of considerable cultural importance. The primary task has two dimensions. The first is concerned with optimizing current teaching for learning and the second with improving future teaching for learning. A task of this kind, its cultural significance and an organizational culture that underpins work on the task are likely to lead to high performance.