Headache is an uncommon symptom in Guillain–Barré syndrome (GBS). We review four clinical settings related to GBS in which headache may be present. We focus on pathophysiological explanations, alerting the clinician to further potential investigations and treatment. Most reports of headache in GBS occur in the context of the posterior reversible encephalopathy syndrome, an increasingly recognized dysautonomia-related GBS complication. Less frequent is headache in the setting of increased intracranial pressure and papilledema (secondary intracranial hypertension), Miller Fisher syndrome, and cerebral venous sinus thrombosis. Rarely, headache can occur secondary to aseptic meningitis from IVIg use.