Guillain–Barré syndrome (GBS) is an autoimmune polyneuropathy characterized by hyporeflexic neuromuscular paralysis and albuminocytologic dissociation in the cerebrospinal fluid. It is a postinfectious disorder. The most common antecedent illnesses are respiratory tract infection and Campylobacter jejuni infection. After the antecedent infection, specific antibodies are generated that cross-react with gangliosides in the host culminating in demyelination of the peripheral nerves or nerve roots. Complement activation also contributes to nerve degeneration. Bilateral symmetrical progression of the limb weakness occurs over a period of a few days followed by a plateau phase, after which a recovery phase follows. Generalized hypotonia and hyporeflexia characterize the limb weakness. Cerebrospinal fluid analysis shows albuminocytologic dissociation. About one-third of patients develop respiratory failure. Neuropathic pain is a disturbing symptom in GBS. Dysautonomia is very characteristic of GBS. Erasmus GBS respiratory insufficiency score predicts the need for mechanical ventilation. The weaning process from mechanical ventilation mainly depends on the recovery of vital capacity and inspiratory force. The definitive treatment for GBS consists of plasma exchange or intravenous immunoglobulin therapy both of which are equally efficacious. Seasonal variation has been observed in the occurrence and recovery of GBS. Prognosis of GBS varies widely. Erasmus GBS outcome scale scoring system predicts the ability of the patient to walk independently after 6 months. Several GBS cases have been reported globally during recent pandemic of coronavirus disease 2019. Though GBS is a self-limiting disease, there are quite a few research questions that still remain to be answered.