The Guillain-Barre syndrome (GBS) is the most common cause of acute paralysis. It requires early institution of therapy to avoid life-threatening complications, to speed up recovery and minimize residual handicap. Advances in supportive care (treatment of infections, anticoagulation) and the introduction of intensive care (assisted ventilation, treatment of autonomic disturbances) have greatly improved the management of this disease and consequently its prognosis. A better understanding of the underlying immune mechanisms prompted pathogenetically oriented therapy. Plasma exchange and high dose intravenous immunoglobulin have been demonstrated in large controlled trials to hasten recovery in GBS. Problems of these studies are discussed and the presumed mode of action of these therapies is reviewed. Corticosteroids have shown no benefit. Ongoing trials are listed and future strategies for immunointervention are outlined.