Five patients with a clinical diagnosis of acute Guillain-Barré polyneuropathy (GBP) had electrically inexcitable motor nerves. All were quadriplegic. One patient died and 3 of the 4 survivors showed poor recovery. Autopsy studies on the patient who died showed severe axonal degeneration in nerve roots and distal nerves without inflammation or demyelination. Electrophysiological studies in these patients suggested that the predominant process was axonal degeneration These cases may represent a separate clinicopathological entity, and constitute a variant of GBP characterized by an acute axonal neuropathy.