Entrustable professional activities (EPAs) have become a popular topic within competency-based medical education programs in many countries and hundreds of publications within only a few years. This paper was written to introduce the ins and outs of EPAs. After a brief historical overview, the rational of EPAs, as a bridge between a competency framework and daily clinical practice, is explained. Next, entrustment decision-making as a form of assessment is elaborated and framework of levels of supervision is presented. For readers interested to apply the concept in practice a stepwise approach to curriculum development is proposed. The paper concludes with an overview of the state of the art of working with EPAs in across disciplines, professions and countries.