Malformations of the cerebral hemispheres are quite variable. The umbrella of hemispheric disturbances can include enlarged ventricles (i.e. ventriculomegaly), cystic abnormalities (e.g. germinal matrix cysts) and migrational abnormalities (e.g. polymicrogyria, pachygyria, cobblestone lissencephaly, heterotopias). Some of these anomalies may be congenital or secondary to destructive or ischemic lesions although porencephaly, schizencephaly and hydranencephaly are typically thought to be mainly secondary to longstanding hypoxic-ischemic injury. This chapter discusses the neuropathological features various cerebral malformations along with what is reported regarding their pathogenesis.