Over the last decades, researchers across the pharmacy practice discipline have increasingly engaged consumers, stakeholders, end-users, patients and individuals from marginalized communities to have active roles in the research process, sharing decision-making to ensure research is relevant and translational in their lives through (participatory) action research (AR). This chapter describes and discusses the content of AR, its historical roots and related concepts. AR methodology is explained and its scientific basis, with a particular focus on action research cycles and questions to ask when doing AR-based studies. The strengths and weaknesses of AR are discussed, just as the chapter provides concrete examples of several AR-based pharmacy practice research illuminating the evidence that AR-based studies have contributed to pharmacy practice. In the last part of the chapter, several tips for carrying out high quality-based action research studies in pharmacy practice are described.