Positive activation and negative activation of glucose metabolism can be detected in different brain regions under acupuncture conditions using functional magnetic resonance imaging (fMRI) which reveals acupoint function and location-acupoint specificity. This study observed the regional cerebral activation of the Waiguan (SJ 5) acupoint following true needling at the true Waiguan acupoint, sham needling at the true Waiguan acupoint and true needling at a sham point using fMRI. The fMRI results demonstrated that compared with sham needling, true needling at Waiguan activated the BA8 area and left cerebellum. Compared with needling at the sham point, needling at Waiguan activated the BA2 area, the left cerebellum and the right inferior semilunar lobule. Thus the activated brain areas caused by needling Waiguan may be the basis for treatment of certain diseases.