This paper argues with evidence that conditions for teacher professional development can be enhanced for mentor teachers through a Learning Centre (LC) project which has been introduced in Hong Kong as a collaborative project between the government, a primary school, a secondary school, and the Hong Kong Institute of Education. The LC teachers perform the role of mentor teachers to enhance professional development of other teachers through web-based workshops or forums, face-to-face teacher education workshops, and school-based support. While the LC teachers are expected to gain professional development themselves as mentors, as suggested in the literature, the environment that may enhance their own professional development is not clear. Using structured interviews, the authors identified the professional development environment that the LC teachers experienced. The paper concludes with recommendations for environmental conditions enhancing the professional development of teachers in schools and conditions to support LC teachers. [Copyright of Teacher Development is the property of Routledge. Full article may be available at the publisher's website: http://dx.doi.org/10.1080/13664530.2010.504018]