The objective is to investigate if patients with metabolic syndrome have a difference in endothelial function (EF) and functional aerobic capacity as they were normotensive or hypertensive. Sixty-three consecutive primary prevention patients who came for the first time to a metabolic clinic, were studied with stress test and flow mediated dilation (FMD). The study was blind for the crossover results. Mean population age was 52 years and 60% among them were men. Ninety percent of patients accomplished metabolic syndrome criteria (by International Diabetes Federation criteria). There was no a significant difference in functional aerobic capacity between normotensive and hypertensive patients, despite it was calculated by METS achieved in the stress test (median 5.81 and 4.63 p=0.114) or by percent of capacity predicted by gender and age (median 79.7% and 63.2% p=0.243).In the whole population we found a significant difference in EF between normotensive and hypertensive (median 10% and 8% p=0.002) and between patients without and with metabolic syndrome (median 11% and 8% p=0.023). In the group of patients with metabolic syndrome we found also a significant difference in EF between normotensive and hypertensive (median 10% and 7.5% p=0.006) but we did not find a significant difference in functional aerobic capacity. Endothelial function was associated to hypertension and waist in multiple linear regression model. We conclude that in this population patients with metabolic syndrome and hypertension have poorer endothelial function than patients with metabolic syndrome and normotension.