In this chapter, we discuss the different ways in which the primate pulvinar has been subdivided, based on cytoarchitectural and myeloarchitectural criteria. One original criterion, based on cytoarchitecture, subdivided the pulvinar into nucleus pulvinaris medialis (PM), nucleus pulvinaris lateralis (PL), and nucleus pulvinaris inferior (PI). Later, the anterior limits of the pulvinar were extended and a subdivision was added to this nucleus, named pulvinar oralis (PO). PO occupies the anterior portion of the pulvinar and appears between the nucleus centrum medianum (CM) and the nucleus ventralis posterior lateralis (VPL).