History of medicine is a branch of history which evaluates the background, emergence, trend, and evolution of medical science and profession. Similar to other related disciplines, research in this field requires adhering to the consensus obtained by scientific methods. Among such studies, the most important steps are selection of the topic, raising questions about the topic, identification of reliable references, discussion and interpretation of the data, and finally conclusion. In this paper, we have briefly addressed the position of history as well as the importance of history of science and medicine, and then concisely discussed the research methodology and its problems in history of medicine.