Five patients with essential tremor had a dramatic diminution in tremor amplitude within 15 minutes of ingesting small doses of ethyl alcohol. The same patients were given equivalent amounts of ethyl alcohol infused into a brachial artery, and there was no decrease in tremor amplitude in the perfused limb. It is concluded that, in patients with essential tremor, ethanol acts in a specific fashion on sensitive structures within the central nervous system and has no effect on peripheral tremorogenic mechanisms. This provides additional evidence for a central mechanism in essential tremor, distinguishing it from other tremors arising primarily from oscillation in peripheral servo-loops.