The effects of alcohol on emotional behavior during social interaction were studied in an experiment utilizing unstructured discussions between male-female couples. All subjects participated in an alcohol (1.0 ml/kg) and placebo session, and a small number took part in a third higher dose session (1.5 ml/kg). Quantitative and qualitative ratings of affect were made from the recorded interactions. Alcohol produced significant increases in the affects of elation--giddiness and happiness--and an overall increase in total emotional expression. Only some aspects of anxiety were affected by alcohol. Hostility and aggressiveness were not increased on two quantitative measures but showed a significant increase on qualitative scores in the low dose session. Although there was no consistent relationship between blood alcohol level and emotional response , drinking history significantly altered emotional response to alcohol (tolerance effects). The euphoric effects of alcohol that we found are discussed in terms of the unique aspects of the experimental situation employed. Some important variable are delineated that may influence responses to alcohol.