Objective: Serum urate levels have been associated with metabolic syndrome (MS). However, the relationship between these two variables in patients with essential arterial hypertension has not been studied. Patients and methods: A Cross-sectional study in 592 patients with essential hypertension. The MS was defined according to the ATP-III criteria. We excluded patients with hypouricemic treatment. Results: The prevalence of MS was 52% (95% CI, 48-56%) and there was a graded increase with increasing serum urate (uricemia <= 4.7 mg/dl, 36%; uricemia >= 6.8 mg/dl, 70%, P < 0.001). Hypertensive patients with MS showed a higher mean uricemia than those without this comorbidity (6.1 +/- 1.5 mg/dl versus 5.4 +/- 1.3 mg/dl, P < 0.0001). The prevalence of hyperuricemia (men, >7.0 mg/dL; women, >6.0 mg/dL) in hypertensive patients without diuretic treatment, was 24% (in those with MS 40% versus 11% without MS). In multivariate analysis, triglycerides (OR = 1.008, CI 95%: 1.004-1.012, P < 0.001) and body mass index (BMI) (OR = 1.118, CI 95%: 1.059-1.181, P < 0.001), were independent predictors of serum uric acid levels. Conclusions: In patients with essential hypertension, about half have MS and one out of four has hyperuricemia. The most important determinant of hyperuricemia is BMI. (C) 2012 Elsevier Espana, S.L. All rights reserved.