Inflammatory demyelinating polyneuropathy (IDP) is a rare neurological disorder in which there is inflammation of peripheral nerves, roots and destruction of myelin sheath. This leads to defect in conveyance of nerve signals and loss of nerve fibers. This causes weakness, paralysis and/or impairment in motor function, especially of the arms and legs (limbs). Types of IDP are acute inflammatory demyelinating polyneuropathy (AIDP) and chronic inflammatory demyelinating polyneuropathy (CIDP) briefly discussed along with their epidemiology, pathogenesis, pathophysiology, diagnostic criteria, and differential diagnosis. This chapter covers the corticosteroids, intravenous immunoglobulin (IVIg), and hematopoietic autologous stem cell transplantation. Corticosteroids are effective in management of CIDP. Some suggested that corticosteroid treatment shows effectiveness in 65–75% of patients with CIDP. Intravenous immunoglobulin administration is useful for short-term effect. Mechanism of action in CIDP is not known. The most common side effects are allergic rashes, fever, easy fatigability, headache, generalized body pain, chest discomfort and high blood pressure.