Guillain-Barré syndrome typically presents with an acute ascending areflexic weakness, progressing over 4 weeks or less. The most common form of the disease is an acute inflammatory demyelinating polyneuropathy, but other forms with primarily axonal pathologies are well documented. The association of Guillain-Barré syndrome with a range of antecedent infections, particularly Campylobacter jejuni enteritis, is also established. A range of serological and neurophysiological investigations can assist in making an accurate diagnosis. Background information about the syndrome and the evidence base for such treatments are discussed herein.