Simulation in medicine is a training technique that makes use of simulated clinical scenarios. Simulation-based training can take place in different ways and with different tools, depending on the learning objectives. Participants can make mistakes and learn from them without risk to the patient, and then transfer the skills and knowledge acquired to real-life situations. The primary objective of simulation in healthcare is the "safety" of the patient and the healthcare worker, with the need to create a quality standard of care dominated by a "culture of safety". This is achieved by improving technical operational skills and the communication skills of healthcare workers. The faithful simulated reproduction of complex clinical situations and their management in team dynamics is an optimal educational context to maximise the reduction of cognitive errors caused by the human factor. Medical simulation is a fully interactive ‘training’ system based on the use of innovative training tools, set in the context of a fully realistic clinical scenario. It is a new method of education that is now an integral part of healthcare training in many countries.