From the earliest days of medical practice, when surgeons used cadavers to explore the possibilities of surgical intervention, simulation has been employed to advance the practice of health care. In the last 10 years, technological advances have allowed for a wider availability and greater realism of simulation, and this has encouraged a great expansion in its use. Simulation aims to create a virtuous cycle of professional development to improve patient outcomes. Although it seems eminently logical to believe that simulation will result in better outcomes, there is a need to test these new training interventions rigorously to be sure of their worth and to understand any limitations. The purpose of this BJOG supplement is to examine in depth several paradigms of medical simulation within maternity care and gynaecology, in different settings, looking at what can be achieved and how. In this opening review, we look at the potential use of medical simulation in broad terms and describe the types of evidence that can be employed to support its use.