Chronic inflammatory demyelinating polyradiculoneuropathy(CIDP) is a rare acquired demyelinating disease of peripheral nervous system(PNS), characterized by relapsing or progressive proximal and distal muscle weakness with possible sensory loss. It is one of several chronic neuropathic syndromes that are believed to have an autoimmune etiology. We experienced a case of CIDP in a 3-month-old boy associated with perianal abscess by Klebsiella pneumoniae who had a precipitous onset of symptoms after anesthesia. He was treated with intravenous immunoglobuline with little improvement but showed a remarkable clinical and electrophysiologic improvement after methylprednisolone pulse therapy. We report this case with a brief review of related literature.