We opted in this study to evaluate the association between metabolic syndrome (MetS) and microalbuminuria in type 2 diabetes. A total of 800 adults (344 males; age 54.8 +/- 9.6 years) with type 2 diabetes were studied. MetS was defined by the International Diabetes Federation criteria and microalbuminuria by urinary albumin excretion between 30 and 299 mg/day on at least two of three occasions. Patients with macroalbuminuria and those with poor renal function were not included. Microalbuminuria was present in 237 (29.6%) patients with MetS and increased in prevalence with increasing numbers of metabolic abnormalities (P < 0.001). The normo- and micro-albuminuric groups were not significantly different in age, sex, and renal function. However, MetS was significantly more common among patients with (90.3%) than those without (76.6%) microalbuminuria (P < 0.01). In multivariate regression, MetS was the strongest correlate of microalbuminuria (OR = 3.31, 95% CI = 1.91-5.75; P < 0.01). In conclusion, MetS is independently associated with microalbuminuria in type 2 diabetes.