Often professional development is seen as something that is provided pre-packaged to teachers who adopt or reject it depending upon their previous beliefs and knowledge. This view does not take into account the influence of context on the professional development. Yet, there is little research from the perspective of the professional development facilitators and so the complexity in which they operate tends to be ignored. In this paper, we explore the constraints and opportunities in the setting up a mathematics professional development project in one school whose students came from a low socioeconomic area. We unpack some of the main decision making points using Kemmis and Grootenboer’s (2008) ideas on the connection between practice architectures and dispositions, as described by Aristotle. By identifying how the circumstances and context shaped the setting up of the professional development, we were better able to understand how we influenced the situation and thus how we affected the later decision making of participants. Such unpacking has potential for better understanding how the rhetoric surrounding Education for All can become a reality.