For some years teacher education and professional development in English language teaching has been moving away from promoting top-down approaches, where teachers are expected to absorb bodies of knowledge and then apply them in the classroom, to more bottom-up perspectives. These perspectives focus on contextualised professional development, where teachers can concentrate on exploring issues of relevance to their daily work. One such approach in this new perspective is action research, a way of conducting investigations into teaching and learning that are directly relevant to the communities and classrooms where teachers work (Burns, 2010). In this talk, I will explain the concept of action research, and its main processes and procedures. My talk will be illustrated with examples of action research I have facilitated with teachers in different parts of the world, which will show the kinds of investigations English language teachers have carried out and what they learned from them.