Eept. Psychiatry and Behavioral Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA This paper reviews recent studies indicating that the marked expansion and differentiation of the prefrontal cortex in primate is associated with an increase in the complexity of both the regional density and laminar distribution of catecholaminergic afferents. The innervation patterns of these systems in monkey prefrontal cortex appear to accurately predict those in human prefrontal cortex, suggesting that studies in nonhuman primate may be reasonably used to generate hypotheses about the nature of involvement of these systems in disorders such as schizophrenia. In addition, the distinctive developmental pattern of the dopaminergic innervation of primate prefrontal cortex and the possibility of an intrinsic catecholaminergic innervation of primate prefrontal cortex may reveal new avenues of investigation into the roles of prefrontal catecholamines in both normal and pathological states.