The relationships between home blood pressure (BP), masked hypertension defined by home BP, and integrated flow-mediated vasodilation (FMD) response remain unclear. The authors enrolled 257 patients (mean age, 63.5 years; 51% men) who had at least one cardiovascular risk factor. FMD of the brachial artery was measured with a semiautomatic edge-detection algorithm. The integrated FMD response was calculated as the area under the dilation curve during 120 seconds after deflation (FMD-AUC120) and the FMD magnitude as the percentage change in peak diameter (ΔFMD). Masked hypertension was defined by office BP <140/90 mm Hg and home BP ≥135 mm Hg and/or 85 mm Hg. Home systolic BP was inversely correlated with FMD-AUC120 and ΔFMD (FMD-AUC120:r=−.23,P<.001; ΔFMD:r=−.13,P=.041), and office systolic BP was inversely associated with FMD-AUC120 (r=−.16,P=.011), but not with ΔFMD. After adjusting for covariates, home systolic BP (β=−.27,P=.003), but not office BP, was inversely associated with FMD-AUC120, whereas ΔFMD was not associated with office or home systolic BP. FMD-AUC120 was significantly lower in patients with masked hypertension compared with those with normotension (7.7±6.7 vs 11.5±8.8 mm × s,P=.048). Home systolic BP and masked hypertension defined by home BP were associated with a decrease in FMD-AUC120.