This review article discusses the use of action research in music education and its potential for producing knowledge and improving practice. The discussion is situated in an analysis of action research studies in music education. The review demonstrates that action research in music education focuses on a wide variety of subject matter, integrates research and action, is collaborative, grounded in a body of existing knowledge, and leads to powerful learning for the participants. However, few action research projects are cyclical, deal with aspects of social transformation, or broad historical, political or ideological contexts, and there is little focus on reflexivity. The review suggests that, in order to undertake high-quality action research, researchers need a good understanding of action research, a focused use of research literature and a defensible position with regard to data analysis and the generation of trustworthy findings.