Early generation β-blockers lower blood pressure and reduce cardiovascular morality in coronary artery disease and congestive heart failure, but worsen glucose homeostasis and fibrinolytic balance. Nebivolol is a third-generation β-blocker which increases the bioavailability of nitric oxide. We compared the effect of nebivolol (5mg/d) and the β1-selective antagonist metoprolol (100mg/d) on glucose homeostasis and markers of fibrinolysis in 46 subjects with metabolic syndrome. Subjects underwent a frequently sampled intravenous glucose tolerance test after 3-week washout and placebo treatment, and following randomized treatment with study drug. After 12-week treatment, nebivolol and metoprolol equivalently decreased systolic blood pressure, diastolic blood pressure, and heart rate. Neither drug affected beta cell function, disposition index, or acute insulin response to glucose. Metoprolol significantly decreased the insulin sensitivity index. In contrast, nebivolol did not affect insulin sensitivity, and the decrease in sensitivity was significantly greater following metoprolol than nebivolol (-1.5±2.5 × 10-4 × min-1 per mU/L versus 0.04±2.19 × 10-4 × min-1 per mU/L after nebivolol, P=0.03). Circulating plasminogen activator inhibitor also increased following treatment with metoprolol (from 9.8±6.8 to 12.3±7.8 ng/mL), but not nebivolol (from 10.8±7.8 to 10.5±6.2 ng/mL, P=0.05 versus metoprolol). Metoprolol, but not nebivolol, increased F2-isoprostane concentrations. In summary, treatment with metoprolol decreased insulin sensitivity and increased oxidative stress and the antifibrinolytic plasminogen activator inhibitor-1in patients with metabolic syndrome, whereas nebivolol lacked detrimental metabolic effects. Large clinical trials are needed to compare effects of nebivolol and the β1 receptor antagonist metoprolol on clinical outcomes in patients with hypertension and the metabolic syndrome.