Seizures are a common cause of EMS activation. This chapter discusses the high quality, moderate and low quality recommendations for seizures. Status epilepticus (SE) is defined as persistent or rapidly recurring seizures lasting for more than 5 minutes that generally do not stop by themselves. Psychogenic non-epileptic spells (pseudo-seizures) are challenging to diagnose in any setting and should be an EMS diagnosis in only the most extreme and obvious presentation. Occasionally, breakthrough seizures reflect lowering of the seizure threshold by some other acute pathology or infection or are caused by withdrawal from alcohol or other substances. The Prehospital Treatment of Status Epilepticus (PHTSE) Trial was a randomized, controlled trial of diazepam, lorazepam and placebo in the prehospital treatment of SE. Importantly, the trial showed that early termination of seizures was associated with better clinical outcomes.