Acute autonomic, sensory and motor neuropathy (AASMN) is a rare peripheral nerve disorder characterized by prominent dysautonomia with somatic sensory and motor impairment. Dysautonomia in AASMN is intractable even with corticosteroid therapy or plasmapheresis. Here we report a case of AASMN with severe orthostatic hypotension. Although the effectiveness of corticosteroid was insufficient, high dose intravenous immunoglobulin therapy (IVIg) was effective for not only sensorimotor symptoms but also autonomic symptoms. This is the first case of AASMN showing favorable responses to IVIg treatment, suggesting that IVIg should be considered when corticosteroid therapy or plasmapheresis is ineffective or insufficient.