Seizures are commonly encountered in the setting of brain injury in neurologic critical care. Though seizure prophylaxis with the use of antiepileptic drugs is frequently utilized in variety of brain injury paradigms, it is often not based on evidence and is controversial. Significant difficulties arise from interpretation of supporting literature due to lack of definitions for early-vs.-late-seizures, variable end points with seizure prophylaxis, as well as methodologic inconsistencies for seizure detection. This descriptive review summarizes the existing literature on the use of prophylactic anticonvulsants in clinical paradigms commonly encountered in neurologic critical care and highlights the important controversies concerning their use.