The first Medical Terminology was published by the Korean Medical Association in 1977 in Korea. Since then 4 more editions of Medical Terminology have been published. The final one, the 5th edition was published in 2009. Among these, in the 3rd edition, almost all of the medical terms were words in Chinese characters. In contrast, the 4th edition had been completely changed. Almost all of the terms were Hangul (Korean language) terms. The 5th edition accepted both terms in Chinese characters and Hangul terms. Owing to this major shift in medical terminology, users of medical terms have been greatly inconvenienced. At present, the Medical Terminology Committee of the Korean Medical Association are carrying out the work of selecting the representative term for each medical term. Medical terms should be easily understandable because medical terms are used by lay people as well as medical doctors. For easy and efficient communication between the doctor and the patient, it is not important whether the term is in Chinese characters or Hangul terms. The work of selecting representative terms should be carried out in rational way. Close communication and cooperation between the Medical Terminology Committee of the Korean Medical Association and each academic medical society in the Republic of Korea is necessary for consistency in establishing medical terminology. A system for collection and translation of medical terms newly coined and imported from abroad should be developed.