Background Plasminogen activator inhibitor type 1 (PA1-I) plays a key role in fibrinolytic activity, which is important for thrombotic cardiovascular events. It has been suggested that moderate alcohol consumption may protect against coronary heart disease and ischemic stroke. However, little is known about the effects of moderate doses of alcohol on PA1-1.Methods and Results We assessed the association between different levels of alcohol consumption and PA1-1 among 1862 participants of the National Heart, Lung, and Blood Institute Family Heart Study. We fitted a regression model, adjusting for anthropometric, metabolic, and lifestyle factors. Individuals in the highest alcohol intake category were leaner, had higher high-density lipoprotein cholesterol levels, smoked more cigarettes, and consumed less dietary fiber compared with never-drinkers. For drinking categories of never-drinkers, ex-drinkers, and current drinkers of 0.1 to 1.4, 1.5 to 4.9, 5.0 to 14.9, and >= 15 g/d of alcohol, multivariate adjusted geometric mean PA1-1 levels among women were 10.77, 9.41, 9.99, 11.21, 11.28, and 16.40 ng/ml, respectively. With similar categories except the top category divided into 15.0 to 29.9 and >=30 g/d, PA1-1 levels among men were 18.43, 15.77, 15.19, 16.20, 17.27, 24.02, and 29.46 ng/mL, respectively.Conclusions These results show that alcohol consumption up to 14.9 g/d is not associated with increased PA1-1, whereas the findings suggest increased PA1-1 with greater alcohol intake.