Moderate alcohol consumption has been associated with a reduction in the risk of myocardial infarction (MI) in men. To evaluate this relation in young women, we studied 513 patients with first infarctions and 918 hospital controls, all of whom were less than 50 years of age. The estimated relative risk of MI for current drinkers, after allowance for potential confounding factors, was 0.7 (95 per cent confidence interval. 0.5 - 1.0), and the apparent reduction in risk was strongest for women drank wine. There was no evidence of an effect among ex-drinkers.