Simulation is a technique used for formal medical education for more than 40 years. Its application has allowed a better training of medical and nursing students, as well as specialists in different clinical and surgical residences and the improvement of invasive and surgical techniques. In addition, by using simulation labs it has been possible to have a more objective education, given the fact that sometimes the access of the student to the patient is limited by ethical, social, administrative or legal parameters. Finally simulation together with the critical reasoning and education based on the resolution of problems has allowed improving and understanding the deep meaning of the competitions. As a technique, simulation offers an objective and a control way to understand the real importance of trial and error as an important pillar for the improvement of skills; besides it represents a method that allows a quality control over education and surgical techniques.