This chapter provides detail description of Cerebral edema in relation to neoplasias of nervous system. Chapter has one well illustrated diagram. Cerebral oedema in relation to neoplasias of nervous sytem, blood-brain barrier, cerebrospinal fluid and hydrocephalus, aquaporins in the brain, cerebral oedema, cytotoxic oedema, vasogenic oedema, hydrostatic oedema, osmotic oedema, hydrocephalic extracellular oedema, brain oedema following trauma, brain tumors and oedema, secondary effects of cerebral oedema raised intracranial pressure, papilloedema and intracranial herniations are described in detail. 71 references are included at the end of the chapter to facilitate further reading.