The term “acupuncture” describes a family of procedures involving the stimulation of points on the body using a variety of techniques. The acupuncture technique that has been most often studied scientifically involves penetrating the skin with thin, solid, metallic needles that are manipulated by the hands or by electrical stimulation. Practiced in China and other Asian countries for thousands of years, acupuncture is one of the key components of traditional Chinese medicine. Although millions of Americans use acupuncture each year, often for chronic pain, there has been considerable controversy surrounding its value as a therapy and whether it is anything more than placebo. Research exploring a number of possible mechanisms for acupuncture’s pain-relieving effects is ongoing. Results from a number of studies suggest that acupuncture may help ease types of pain that are often chronic such as low-back pain, neck pain, and osteoarthritis/knee pain. It also may help reduce the frequency of tension headaches and prevent migraine headaches. Therefore, acupuncture appears to be a reasonable option for people with chronic pain to consider. However, clinical practice guidelines are inconsistent in recommendations about acupuncture and many effects may be due to the placebo effect or context effects. The effects of acupuncture on the brain and body and how best to measure them are only beginning to be understood. Current evidence suggests that many factors—like expectation and belief—that are unrelated to acupuncture needling may play important roles in the beneficial effects of acupuncture on pain.