Acute Inflammatory polyneuropathies are an important group of neuromuscular disorders and are referred to collectively as Guillain-Barré syndrome (GBS). Our knowledge regarding pathogenesis, diagnosis and management continues to expand, resulting in improved opportunities for identification and treatment. These autoimmune processes cause neuropathy by affecting various structures (myelin or axons), at different locations (nerve root, nerve cell bodies or peripheral nerve) with a variety of patterns. Most clinical neurologists will be involved in the management of patients with these disorders, and there are now a variety of reasonable therapies available for acquired demyelinating neuropathies. In this report, we review the distinctive clinical, laboratory and electro-diagnostic features that aid in their diagnosis, with emphasis on clinical characteristics that are of paramount importance in diagnosing specific conditions and determining the most appropriate therapies, and helpful in determining long-term prognosis.