In recent years, investigators have used a variety of techniques to study human neurotransmission in health and disease. One of the most promising of these techniques is molecular or neurotransmitter imaging, which, despite being an emerging technique, has made significant contribution to our understanding of human neurotransmission (1,2). Molecular imaging has been used by numerous investigators to establish maps of the functional anatomy of neuroreceptorradioligand interaction (3,4). Recently, it has been applied to the detection of dynamic changes in neurotransmitter activity induced by behavioral, cognitive, or pharmacologic interventions (5-12). This chapter includes a brief outline of the basic concepts of neurotransmitter imaging, important information acquired using this technique, and a discussion of dynamic receptor imaging.