We examine teachers' experiences of a major reform of the school science curriculum for 14-16-year olds in England. This statutory reform enhances the range of available science courses and emphasises the teaching of socio-scientific issues and the nature of science, alongside the teaching of canonical science knowledge. This paper examines teachers' experiences of the reform and the factors that condition these experiences. A designed sample of 22 teachers discussed their experiences of the reform within a semi-structured interview. Our analysis considers how the external and internal structures within which teachers work interact with the personal characteristics of teachers to condition their experiences of the curriculum reform. In many cases, personal/internal/external contexts of teachers' work align, resulting in an overall working context that is supportive of teacher change. However, in other cases, tensions within these contexts result in barriers to change. We also explore cases in which external curriculum reform has stimulated the development of new contexts for teachers' work. We argue that curriculum reformers need to recognise the inevitability of multiple teaching goals within a highly differentiated department and school workplace. We also show how experiences of curriculum reform can extend beyond the learning of new knowledge and associated pedagogies to involve challenges to teachers' professional identities. We argue for the extended use of teacher role models within local communities of practice to support such "identity work". (Contains 7 notes and 2 tables.)