Traditional Korean medicine (known in North Korea as Koryo medicine) refers to the forms of traditional medicine practiced in Korea.

Korean medical traditions originated in ancient and prehistoric times and can be traced back as far as 3000 BCE when stone and bone needles were found in North Hamgyong Province, in present-day North Korea. In Gojoseon, where the founding myth of Korea is recorded, there is a story of a tiger and a bear who wanted to reincarnate in human form and who ate wormwood and garlic. In Jewang Ungi (제왕운기), which was written around the time of Samguk Yusa, wormwood and garlic are described as 'edible medicine', showing that, even in times when incantatory medicine was the mainstream, medicinal herbs were given as curatives in Korea. Medicinal herbs at this time were used as remedial treatment such as easing the pain or tending injury, along with knowing what foods were good for health. In the period of the Three Kingdoms, traditional Korean medicine was mainly influenced by other traditional medicines such as ancient Chinese medicine. There was important trade with foreign countries during the period of the Three Kingdoms. "In particular, medical knowledge from China and India supplemented the foundation of traditional medicine that had been handed down from the Old Joseon period." In Korea, this has "spurred further developments."

Medicine flourished in the period of the Joseon. For example, the first training system of nurses was instituted under King Taejong (1400–1418), while under the reign of King Sejong the Great (1418–1450) measures were adopted to promote the development of a variety of Korean medicinal ingredients. These efforts were systematized and published in the Hyangyak Jipseongbang (향약집성방, 1433), which was completed and included 703 Korean native medicines, providing an impetus to break away from dependence on Chinese medicine. The medical encyclopaedia named Classified Collection of Medical Prescriptions (醫方類聚, 의방유취), which included many classics from traditional Chinese medicine, written by Kim Ye-mong (金禮蒙, 김예몽) and other Korean official doctors from 1443 to 1445, was regarded as one of the greatest medical texts of the 15th century. It included more than 50,000 prescriptions and incorporated 153 different Korean and Chinese texts, including the Concise Prescriptions of Royal Doctors (御醫撮要方, 어의촬요방) which was written by Choi Chong-jun (崔宗峻, 최종준) in 1226. Classified Collection of Medical Prescriptions has very important research value, because it keeps the contents of many ancient Korean and Chinese medical books that had been lost for a long time.

After this, many books on medical specialties were published. There are three physicians from the Joseon Dynasty (1392–1910) who are generally credited with further development of traditional Korean medicine—Heo Jun, Saam, and Yi Je-ma. After the Japanese invasion in 1592, Dongeui Bogam (동의보감) was written by Heo Jun, the first of the major physicians. This work further integrated the Korean and Chinese medicine of its time and was influential to Chinese, Japanese and Vietnamese medicine. In the late period of Joseon, Yi Je-ma's "unique system of constitutional medicine" illustrates the "nature of" the medicine that has been traditionally developed in Korea by example. Medical treatments were based upon yin and yang principles "and the five elements." A warm treatment would treat a person who is a yin. On the other hand, a cold treatment would treat a person who is a yang.

The next major influence to traditional Korean medicine is related to Sasang typology (사상의학). Yi Je-ma and his book, The Principal of Life Preservation in Oriental Medicine (東醫壽世保元, 동의수세보원) systematically theorized with the influence of Korean Confucianism and his clinical experiences in Korea. Yi Je-ma said that even if patients suffer the same illness, patients need to use different herbal applications to treat the same illness due to the pathophysiologies of individuals. He stresses that the health of human body had a close relationship with the state of mind. He believed that the human mind and body were not separate and they closely reflected each other, and the aspect of mind needed to be considered when examining the causes of disease. Thus, not only food and natural environment but also emotional changes in humans can be another major reason for illness. He believed that medical diagnosis and treatment should be based on person's typology rather than on symptoms alone and each person should be given different prescriptions depending on the constitution of the individual. Sasang typology (사상의학) focuses on the individual patients based on different reactions to disease and herbs. Treat illness by the treatment of the root cause through proper diagnosis. Key to this diagnosis is to first determine the internal organs or pathophysiology of each patient.

The next recognized individual is Saam, a priest-physician who is believed to have lived during the 16th century. Although there is much unknown about Saam, including his real name and date of birth, it is recorded that he studied under the famous monk Samyang. He developed a system of acupuncture that employs the five element theory.

In the late Joseon dynasty, positivism was widespread. Clinical evidence was used more commonly as the basis for studying disease and developing cures. Scholars who had turned away from politics devoted themselves to treating diseases and, in consequence, new schools of traditional medicine were established. Simple books on medicine for the common people were published.

Yi Je-ma classified human beings into four main types, based on the emotion that dominated their personality and developed treatments for each type: