Alcohol has been consistently demonstrated to elevate blood pressure (BP) in intervention studies in men. There are uncertainties, however, as to the nature of the relationship in women. We, therefore, determined in healthy premenopausal women the dose-dependent effects of alcohol on ambulatory BP. Twenty-four participants aged 25 to 49 years, with a mean alcohol intake of 202±94 g alcohol/wk and mean 24-hour systolic and diastolic BP of 110.2±8.9/68.9±5.7 mm Hg, were randomized to a 3-period cross-over study. Each evening they consumed higher volume red wine (lower level drinkers, 146 g alcohol/wk; higher level drinkers, 218 g alcohol/wk), lower volume red wine (lower level drinkers, 42 g alcohol/wk; higher level drinkers, 73 g alcohol/wk), or dealcoholized red wine, each for a period of 4 weeks. Higher volume red wine significantly increased 24 hours systolic and diastolic BP relative to dealcoholized red wine (by 2.0±0.6/1.2±0.4 mm Hg; P=0.001 and P=0.028, respectively). There were similar changes for higher volume red wine relative to lower volume red wine (by 1.6±0.6/1.4±0.4 mm Hg; P=0.014 and P=0.005, respectively). These effects were predominantly on awake rather than asleep BP. There was no significant difference in BP between lower volume red wine and dealcoholized red wine. We conclude that in healthy premenopausal women regular consumption of alcohol as 200 to 300 mL red wine/d (146-218 g alcohol/wk) elevates 24 hours systolic and diastolic BP. The magnitude of the increase in BP is similar to that previously reported in intervention studies in men.