erformance-based education can be described as an educational method to foster clinical skills as well as clinical knowledge of medical students. Studies show that performance-based methods are effective for teaching a whole gamut of knowledge, clinical skills, and attitudes (1,2). There is a tendency towards performancebased teaching and assessment in medical education (3) and it has been highlighted by General Medical Council (GMC) and the Association of American Medical Schools. This can be achieved by early clinical practice which is necessary in both undergraduate and postgraduate medical education. In this regard, real patients as a resource for teaching a wide range of clinical communication and examination are inevitably precious. In respond to such necessity, it is important to provide more opportunities for medical students to practice in a safe and controlled environment to gain mastery over essential clinical skills and knowledge prior to entry in a real life clinical setting. Thus, the use of simulation has become widespread in many health professions. Simulation, an old phenomenon, is ubiquitous in almost every fields of human endeavor. It is commonplace in fields such as military, aviation, space, Standardized patients versus simulated patients in medical education: are they the same or different