Alcohol-related expectancies can influence the behavioral effects of alcohol and decisions regarding alcohol use. A standard measure of expectancies is needed for research and clinical work in the alcohol arena; the development and current status of the Alcohol Expectancy Questionnaire (AEQ) is summarized. The adolescent and adult forms of this instrument are designed to measure the degree to which individuals expect alcohol to produce a variety of general and specific effects. Research with the AEQ indicates a consistent relationship between alcohol expectancies and alcohol consumption, alcohol abuse and behavior while drinking. Data bearing on the psychometric properties and clinical and research utility of the AEQ are discussed.