Extensive cortical and subcortical areas in the rhesus monkey are involved in processing visual information. The full extent of these areas has been delineated by application of the [14C] 2-deoxyglucose method and comparison of metabolic activity in visually stimulated versus visually deafferented cerebral hemishperes. The visual-nonvisual borders of two cortical visual pathways, an occipito-temporal pathway known to be critical for object vision and an occipito-parieto pathway known to be critical for spatial vision, have been specified. In addition, their points of intereaction with prearcuate and inferior prefrontal cortex and with limbic, striatal, and diencephalic structures were identified. We have also quantified the functional contribution of the forebrain commissures to vison through a comparison of monkeys prepared with complete vs partial visual deafferentation of one hemisphere (i.e. optic tract section plus forebrain commissurotomy vs. optic tract section alone, respectively). Finally, we have identified some of the cerebral areas subserving multimodal functions through a comparison of monkeys given visual stimulation only and others given visual plus somatosensory stimulation.