GBS is an acquired, monophasic illness of the peripheral nervous system that usually presents with a gait disturbance and clinical features of pain, weakness, and areflexia. The etiology of the disease is immune-mediated and directed against the peripheral nervous system myelin, axon, or both. A careful history, physical examination, and routine laboratory tests are necessary to make a clinical diagnosis and to exclude other disorders that cause acute weakness. Laboratory tests that support the diagnosis, such as an increased CSF protein and abnormal electrodiagnostic studies, may be normal early in the illness. The most serious complications during the acute phase of the disease are respiratory failure and autonomic disturbances. Plasma exchange or IVIG shortens the duration and severity of the disease significantly. The prognosis for children who have GBS generally is excellent for full and functional recovery, using modern intensive care for respiratory support and the management of other complications.