We report a 7-year-old girl with severe Guillain-Barré syndrome (GBS) who showed dramatic improvement after immunoabsorption therapy. She had progressive muscle weakness with resultant respiratory failure. On the 7th day of the illness, she was nearly quadriplegic and dependent on mechanical ventilation. In addition, she had autonomic manifestations, areflexia, abolished or delayed peripheral nerve conduction, and increased CSF protein. Administration of a high dose of gammaglobulin failed to improve the symptoms. Immunoabsorption therapy using a tryptophan column was performed 9 times during 17 days. After 5 times of immunoabsorption therapy, the muscle weakness improved dramatically; she was extubated 16 days after the institution of the therapy and walked without assistance on the 41st day. She regained normal muscle power without any sequelae. The immunoabsorption therapy caused hemolysis and decrease of serum fibrinogen, but no serious complications. The clinical course of this patient suggests the efficacy of immunoabsorption therapy in GBS.