There are many neuropathological findings in autism spectrum disorder (ASD). Some of the reported findings can be accounted by either methodological flaws, the effects of preagonal/agonal conditions, artifacts of postmortem tissue, or as being secondary to comorbidities. A few findings remain that by themselves are abnormal and symptomatic, e.g., heterotopias, cortical malformations (dysplasias). The presence of heterotopias and cortical dysplasias in ASD suggests abnormalities of germinal cell division and their subsequent migration to the cortical plate. In this panel we will discuss and illustrate the available evidence for a neuronal migratory disturbance in ASD. The lectures will summarize the following findings in the brains of ASD individuals: 1) Computerized image analysis studies will provide quantitative evidence of increased neuronal cellularity within the white matter of the brain, especially the subplate region, 2) Serial sections of whole brain specimens will detail the presence of heterotopic clusters of cells and cortical dysplasias, 3) Immunocytochemical staining of the cerebral cortex will illustrate abnormalities of specific interneurons in regards to their location within the laminae of the cerebral cortex, and 4) We will summarize genetic evidence for the roles of disturbed neurogenesis and network desynchronization in autism.