1. Membrane glycoconjugates include glycoproteins and glycolipids that have many important functions in a wide variety of tissues, especially brain. 2. Alcohol's ability to fluidize and swell plasma membranes could be expected to alter the orientation and conformation of the embedded glycoconjugates. 3. Both kinds of glycoconjugates can contain terminal moieties of sialic acid, which has been shown to be decreased by single doses of alcohol. Chronic exposure to alcohol may have no effect on sialic acid, except in very young animals. 4. Glycolipids containing sialic acid (gangliosides) are also decreased by acute doses of alcohol, but chronic alcohol has little effect. Thus, gangliosides may have a role in the development and expression of tolerance. 5. Glycoproteins containing sialic acid may also be involved in alcohol action, but there has been less research in this area. 6. Alcohol-induced disruptions in membrane glycoconjugates could affect the important cellular functions that glycoconjugates have, and thus research on alcohol effects on glycoconjugates could lead to important discoveries of diagnostic and therapeutic value for alcohol abuse and alcoholism.