This chapter presents the clinical overview and mechanistic causes of status epilepticus (SE). SE is an acute neurological emergency that most commonly occurs at the extremes of life and is associated with mortality and significant neurological sequelae. Derived epidemiological values for the incidence of SE depend on several factors including the operational definition of SE employed, the type of study performed, the population studied, and catchment area. The range of etiologies of SE include trauma, brain tumors, vascular diseases, infections, non-compliance with or change in antiepileptic drugs (AEDs), and alcohol withdrawal. The current drugs of first line in the treatment of SE are the benzodiazepines phenytoin or its prodrug, fosphenytoin, and Phenobarbital. Current second-line treatments include intravenous sodium valproate and levetiracetam. Most of our current knowledge on the basic mechanistic causes underlying SE are extrapolated from data obtained from experimental animal models of convulsive SE.