Twenty-one male managers who normally drink moderate amounts of alcohol participated in a placebo-controlled, double-blind, crossover experiment. Subjects consumed either placebo or alcoholic drinks to attain a breath alcohol level of 0.10 during the evening before participation in Strategic Management Simulations. By the time of arrival at the simulation laboratory on the following morning, breath alcohol levels were measured at 0.00. Questionnaire responses indicated considerable hangover discomfort. Responses to semantic differential evaluative scales suggested that research participants evaluated their own managerial performance in the simulation setting as impaired. However, multiple (validated) measures of decision-making performance obtained in the simulation task did not show any deterioration of functioning. Previous research had shown considerable performance decrements in the same task setting, while blood/breath alcohol levels ranged from 0.05 through 0.10%. Apparently, complex decision-making competence by persons who normally consume moderate amounts of alcohol may not be impaired by hangover caused by intoxication during the previous evening that remains at or below a blood alcohol level of 0.10.