Acupuncture is an ancient Chinese therapy with its mode of action unclear and efficacy inconclusive. A lack of attention given to the role of psychosocial context presented in clinical provision of acupuncture may mainly account for the current dilemma in acupuncture research. This psychosocial context induces various cognitive and affective processes in the patient while receiving this treatment. On the basis of the analysis of these psychological factors involved in clinical provision of acupuncture and in light of prior studies on the placebo effect, the author hypothesizes that acupuncture works through potentiation and modulation of a highly organized and somatotopic network of endogenous opioids that links expectation, attention and body schema. This hypothesis, which focuses on the contextual factors involved in clinical provision of acupuncture, has immediate clinical and experimental implications and will take the acupuncture debate much further forward.