Acute pandysautonomic neuropathy(APN) is an uncommon clinical entity involvement vasomotor, sudomotor, pupilomotor, secretomotor and other autonomic systems. Both sympathetic or parasympathetic fibers are involved with relative preservation of somatic sensory and motor function. Although APN shares several clinical features with GBS, it is not clear whether APN is a subvariety of GBS. We reported two young patients with APN. Patient I1 was a 18-year-old girl with recurrent fainting spells. Patients 2 was a 23-year-old man suffering from unexplained nausea and vomiting. Both had a history of previous upper respiratory infection. They presented with gastroparesis, anhydrosis and orthstatic hypotension. Mild numbness and tingling sense was present, but motor power was infact. Neurologic examination showed bilateral tonic pupil, decreased pain and vibration sense, and absent tendon reflexes. Nerve conduction study indicated diffuse sensorymotor polyneuropathy. Nerve biopsy in patient 2 revealed axonal degeneration. After conservative management, gastrointestinal symptoms were improved in patient 2, however, dysautonomic symptoms in young patient may indicate the diagnosis of APN. Although the natural course is generally benign, accurate diagnosis and proper management may be mandatory for the better clinical outcome.