Guillain-Barré syndrome (GBS) is one of the most common acquired neuropathies. In the past GBS was viewed as a unitary disorder, and currently it is believed to be a group of subtypes of acute autoimmune neuropathies. These include classic acute inflammatory demyelinating polyradiculopathy (AIDP), acute motor axonal neuropathy (AMAN), acute motor-sensory axonal neuropathy (AMSAN), Miller Fisher syndrome (MFS) and other rare subtypes. Current knowledge of pathogenesis of each GBS subtype and the role of antecedent infections are reviewed. Clinical characteristics of GBS and updated diagnostic and therapeutic methods are discussed, with special emphasis on immunotherapy and intensive care.