This article explores what it means for teachers to engage in and evaluate students' character education, by examining the connections between action research and Aristotelian virtue ethics. These connections are explored in two ways. Firstly, the article examines what perspective action research has on how moral education, understood in an Aristotelian way, can be implemented and evaluated. While character education may be hot in educational theory, academic advances have not always reached teachers, heads of school, policy-makers and politicians. Secondly, a specifically Aristotelian approach to action research is explored that may help teachers to understand how action research about character education in schools can best be conducted. After a comparison of the three major action research paradigms, "Aristotelian action research" is described as a kind of dialogical enquiry that contributes to the growth of teachers' practical wisdom, which, in turn, has an effect on children's character development. The article ends with suggestions as to how research about character education could be improved if we shift our attention from making character programmes more "effective" to extending and refining teachers' own practical wisdom and virtue.