Guillain Barre Syndrome (GBS) is an immune polyradiculoneuropathy that presents with ascending bilateral lower extremity weakness and areflexia and that affects all age groups with a slight male predisposition. GBS is an important cause of acute neuromuscular paralysis. It is an acute onset, monophasic, immune – mediated polyneuropathy that often follows an antecedent infection. Controlled epidemiological studies have linked it to infection with Campylobacter jejuni in addition to other viruses, including Cytomegalovirus and Epstein Barr virus. It is characterized by motor difficulty, absence of deep tendon reflexes and paraesthesia without objective sensory loss. Etiology of GBS remains unclear and pathophysiology includes demyelination of spinal nerve roots. Death is rare. Early diagnosis and prompt referral should occur in severe cases due to the incidence of potential ventilatory failure and cardiovascular instability in some patients. Treatment of patients with GBS depends on whether they have mildly acute, severely acute or chronic involvement.