The possibility of abolishing pain during operations by needling acupuncture points was detected in China 20 years ago. During the last years the Western World showed great interest in this method, which was tested in a great number of surgical operations. Acupuncture was successful, especially when it was introduced by a short conventional anesthesia. Of special importance seems the possible reduction of anesthetic agents. Though the mode of action of acupuncture cannot yet be explained completely, there exist three different hypotheses: Hypnosis and suggestion, neurophysiological and humoral mechanisms. An actual review on experiments concerning these theories is given.