The Hyperbaric Oxygen Therapy Center, originally the Department of Undersea and Hyperbaric Medicine, was founded at the Tingjhou facility of Tri-Service General Hospital in 1998, aiming to provide medical service of hyperbaric oxygen (HBO2) for people who engaged in diving activities or hyperbaric works facing specific health and safety problems. As the Hospital moved to Neihu in 2000, a brand new HBO2 facility was set up for dual purposes, i.e. clinical service of diving medicine and investigation of new indications. In 2005, in order to fulfill the rapidly increasing need of emergent and critical care of HBO2, we started to assemble all the necessary devices specified only for HBO2, such as ventilator, blood pressure monitor, and transcutaneous PO2 measuring system. The “critical care in HBO2” eventually becomes a featured medicine of Tri-Service General Hospital. To recruit more physicians for emergency and critical care, the HBO2 center was merged into the Division of Pulmonary and Critical Care in 2009. A core HBO2 team was formed with physicians and technicians, who are all well-trained in hyperbaric medicine and chamber operation. Our cooperatives in this hospital include surgeons and physicians specialized in cardiovascular, neurological, otolaryngeal, and plastic wound care, as well as in emergency medicine. Currently, this center serves more than 5000 person-time of HBO2 treatment annually. In addition to the medical service to patients, we provide training courses for HBO2 physicians and technicians coming from hospitals around this country. An average of 15 trainees in each year finished their training course here and got the certificate from Taiwan Undersea and Hyperbaric Medical Society. With a spirit that constantly aspires self-improvement, the Hyperbaric Oxygen therapy Center continues to elevate the overall level of emergency and critical care. The critical care in HBO2 has became a featured medicine of Tri-Service General Hospital and was recognized as 2013 Symbol of National Quality in Taiwan. We hope that our whole-hearted service will become the primary choice of the public seeking high quality of hyperbaric oxygen therapy.