This study is an empirical account of the professional development (PD) practices that constituted part of the work of a group of teachers and school-based administrators working together in a cluster of six schools in southeast Queensland, Australia, during a period of intense educational reform. The data comprise meeting transcripts and interviews with teachers and administrators involved in a reform-oriented professional development initiative over an 18-month period. To analyse these teacher learning practices as teachers' work in this context, the article draws upon Bourdieu's theory of practice, particularly his understanding of the social world as comprising multiple social spaces, or "fields", each characterised by contestation over the practices of most value. The data reveal the field of teachers' work, in which much of the teacher learning transpired, as influenced by a broader instrumental culture; this culture developed in response to teachers' concerns about how to respond to state educational provision initiatives in a more neoliberal global era. These instrumental logics were evident in superficial compliance with and reflection upon educational reform and the continuation of individualistic, workshop-based PD practices. However, at the same time and in keeping with fields as contested, there is also evidence of teachers' participation in more sustained PD practices--involving teachers actively engaging with the content of educational reform, participating in robust reflection about their practice and collaborating in substantive communities of learners. The findings also suggest the need to explicitly support substantive PD within the field of teachers' work in order to challenge more administrative and instrumental pressures to engage in reform. Such a response will assist in fostering the conditions for the generation of a more truly student-centred, collaborative and reflective habitus amongst teachers. (Contains 1 note.)