Since the original report, acute paralysis and albuminocytologic dissociation have remained hallmarks of the Guillain-Barré syndrome but the initially described favorable outcome with complete motor recovery is not always observed. Guillain-Barré syndrome can be complicated by early respiratory distress, dysautonomia and late functional impairment. The conduction block induced by acute demyelination accounts for the spontaneous neurological improvement. On the other hand, early axonal damage or sustained demyelination can be responsible for residual deficit. The cause and mechanism of the disease still remain unclear. For these patients, general care is essential and should be provided in appropriate hospital units. Today, specific treatment consists of either plasma exchange or high-dose intravenous immunoglobulins; the choice depends on their respective contraindications.