Guillain-Barre syndrome (GBS) is a rare disease triggered by postinfectious mechanisms. The disease concerns all ages, and is widely distributed around the world. The principal risks are respiratory failure, especially during the initial phase of the disease, and persisting deficit at long term. Among the infectious known agents, Campylobacter jejuni and CMV represent more than 40% of GBS causes. The clinical presentation, and the long-term prognosis of GBS related to these two etiologies are different. The physiopathological mechanisms of the nervous attack are probably also different. There is no proof, at this time, that anti-infectious treatment can improve the prognosis. The treatment is based on the early use of immunomodulatory treatments like intravenous immunoglobulins or plasma exchanges.