Following the establishment of the Department of Anesthesiology at the Faculty of Medicine, King Chulalongkorn Memorial Hospital in 1965, there was a significant shortage of anesthesiologists. As a result, physicians interested in the field were trained to become anesthesiologists. In 1967, Professor Dr. Niyom Chimchavong and Professor Emeritus Dr. Sriporn Wanikiet initiated regular lectures and patient case discussions for the three trainees at that time. Later, the training evolved into a more systematic and international curriculum.

In 1973, the hospital officially began a residency training program in anesthesiology and introduced a postgraduate clinical diploma in Anesthesiology under the Graduate School of Chulalongkorn University.

Consequently, a Pain Management Unit was established. Pain is the most common reason patients seek hospital care. Pain management plays a vital role across all medical specialties. The World Health Organization has designated pain as the fifth vital sign and affirmed that proper pain relief is a basic patient right. Inadequate pain management can lead to complications or chronic, complex conditions that may prolong hospitalization and negatively affect patients, families, and society.

Medical advancements have increased patient survival, but recurring pain is now more common — such as in cancer, post-surgical pain syndrome, and pain from chemotherapy or radiation side effects. Additionally, the prevalence of work-related conditions or age-related degeneration has increased, including back pain, neck pain, chronic joint pain (chronic musculoskeletal pain), and neuropathic pain.