Objective: To establish whether an association exist between each component of Metabolic Syndrome (MS) and increased natriuresis. Methodology: We analyzed 998 subjects of 48, 8 ± 0.35 years of age and measured: Body Mass Index (BMI), Waist Circumference (WC), Systolic Blood pressure (SBP), Diastolic (DBP), glycemia, lipid profile and urinary electrolyte excretion in 24 hours. Results: The high WC was the most frequent parameter (61,6%), natriuresis was higher in subjects with MS compared to those without SM (173 ± 4.9 vs. 157 ± 2.7 mEq / 24 hours) (p <0.0032), and only significantly correlated with BMI, WC, SBP and DBP (r = 0.394, 0.293, 0.183 and 0.214 respectively, p <0.0001). Conclusion: increased natriuresis in MS subjets, seems to depend on adiposity, but not related to changes in glycemia or lipemia.FONACIT subproyecto S1.20010000679, CDCH a t subproyectos 06-006247-2006, PI06-00-6248.2006, PG06.00.6513.2006 y 06-7273-2008.