Today, “Computer Decision Support Systems” are designed and used in various fields of science. In this new atmosphere, “Expert Systems”, as a sub-branch of Artificial Intelligence, play a central role. In Expert Systems, decisions are made by the computer. Expert Systems are knowledge-based systems that initially acquire knowledge from an expert person, and then transfer it to the computer, so that by making decisions based on the data collected, they can be of help to humans. So far, many Expert Systems have been presented in various fields like industry, control, space, financial decisions, etc.Expert Systems have also found their way into medicine. For example; Dendral software program (1965) to describe and express molecular structure, MYCIN software (1976) for diagnosis of coronary heart diseases, VM for monitoring Intensive Care patients, CADCUCEUS for diagnosing internal medicine related diseases, BLUEBOX for diagnosis and treatment of depression, as well as systems that detect acidic electrolytes, and management of anesthesia education.