Whole hemisphere autoradiography (WHA) with selective high-affinity radioligands is a new tool in studying the distribution of receptors and of other neuronal components postmortem in brains from controls vs. subjects with psychiatric and neurologic diseases. WHA can be performed with several different isotopes (e.g., 3H, 125I, and 11C), and is in addition to characterization studies also used as a tool in early radioligand development. Moreover, using this technique, high-resolution images are obtained that are complementary to those obtained in vivo with e.g., PET and SPECT. Results on dopamine and serotonin receptor subtypes as well as of their transporters show that WHA is a very suitable technique for the detailed characterization of the distribution in the whole human brain.