Abstract: The highly competitive offer of medical training programs and schools, globalization and constant mobility of physicians and medical students (MS), and the commitment to society to deliver competent physicians, demands the definition of performance standards. This would allow to make their performances comparable no matter where they studied or which textbook did they used as reference, to have evaluation mechanisms that guarantee mastery of the integral evaluation of the performance. Assessment has been the key in the teaching-learning process as this obtains a formative and summative element, at different moments, from the extent to which the students have acquired knowledge, skills and attitudes. The progress of the learner must be enhanced with effective feedback on their performance and self-direction of the results obtained in each of the mechanisms established. If, traditionally, this has been considered as the accreditation of compliance with a standard, the evaluation also functions in an integral way as a formative process that identifies advances and deficiencies in the training of residents that allows the definition of actions and strategies for improving the operation of the programs. Different assessment mechanisms are associated with the areas of competence domain, some of the most common tools are: theoretical exams, checklists and rubrics, portfolio, projects and challenges. However, the importance of defining standards which are perceived as fair and designed according to the learning objectives remains a priority to guarantee the credibility of the evaluation agencies and institutions. Some strategies to assure credibility include the involvement of expert and trained evaluators, allowing the process to be carried out with transparency and diligence, and the principles employed should be supported by educational research.