In 1994, the Aga Khan University, Institute for Educational Development (AKUIED) started a new master’s programme for mid-career teachers. The graduates of the programme went out to become ‘Professional Development Teachers (PDTs)’. In this paper one PDT describes her work in the school that sponsored her, and in the AKU-IED. The discussion draws upon examples from her work with a mathematics teacher. Findings indicate that the model of teacher development proposed by the AKU-IED has potential for teacher growth because it incorporates features of some robust forms of teacher development such as mentoring and coaching including cycles of supported planning, demonstration and feedback.