This article explores the ethical dimensions of what Cochran-Smith and Lytle have termed the dialectic of practitioner inquiry. The article argues that the reflexive nature of the theory/practice dynamic means that, in the context of sustained practitioner inquiry, the ethics of research and the ethics of practice both hold the potential to be shaped by and to shape the other. Elsewhere in discussions of the issue of quality in practitioner and other practice-based research, Groundwater-Smith and Mockler have argued that ethical professionalism can and does work as a platform for quality, pushing practitioner inquiry ‘beyond celebration’.