The "Neurobiological Correlates of Acupuncture" Conference was convened November 17-18, 2005 in Bethesda, Maryland. The conference was sponsored by the National Center for Complementary and Alternative Medicine (NCCAM) of the National Institutes of Health (NIH), U.S. Department of Health and Human Services (DHHS). Its goals were to encourage exchange of ideas regarding the direction of neuroimaging in acupuncture research as well as to discuss some of the challenges in this field. The use of neuroimaging, a relatively recent advance in the study of acupuncture, holds the promise of localizing and characterizing brain activity associated with acupuncture interventions in real time and in a minimally invasive way. Among the main challenges to research into the biological mechanisms of acupuncture are the multiple treatment variables and the difficulties of selecting appropriate experimental controls. Despite these challenges, numerous findings from acupuncture neuroimaging experiments were presented and discussed at the conference on topics related to possible signaling networks, sham acupuncture controls, acupoint specificity, acupuncture analgesia, acupuncture-associated brain response, and the potential for using neuroimaging in conjunction with translational and clinical acupuncture research. Future directions in acupuncture neuroimaging research, as recommended by conference participants, should focus on (1) continuing exploration of acupuncture signaling networks; (2) establishing standards and recommendations for performing and reporting acupuncture neuroimaging results; (3) enabling data sharing in the acupuncture neuroimaging community; (4) gaining a better understanding of placebo and control groups in acupuncture neuroimaging experiments; and (5) developing biomarkers that relate to physiologically and/or clinically relevant acupuncture responses to neuroimaging results.