A group of 39 patients with alcoholic polyneuropathy (Alc) and another group of 33 patients with carbon disulphide polyneuropathy were studied by electrophysiological methods using an identical programme, and the results were compared. In both groups evidence was found of damage to the peripheral neuron of the type of axonal neuropathy with signs of axonal loss, with moderate slowing down of conduction velocity and with associated signs of regeneration. The dynamics of changes in the Alc group was greater. The cause of a slower rate of changes in the CS2 group seems to be related to a more gradual exposure to the damaging agent, while in alcohol-dependence the toxic agent has a more acute action, with remissions during abstinence and exacerbations during increased alcohol consumption.