Background: The metabolic syndrome is a common risk factor for cardiovascular disease. Objective: To examine the association between the metabolic syndrome and risk for chronic kidney disease and microalbuminuria. Design: Cross-sectional study. Setting: The Third National Health and Nutrition Examination Survey. Patients: Participants 20 years of age or older were studied in the chronic kidney disease (n = 6217) and microalbuminuria (n = 6125) analyses. Measurements: The metabolic syndrome was defined as the presence of 3 or more of the following risk factors: elevated blood pressure, low high-density lipoprotein cholesterol level, high triglyceride level, elevated glucose level, and abdominal obesity. Chronic kidney disease was defined as a glomerular filtration rate less than 60 mL/min per 1.73 m2, and microalbuminuria was defined as a urinary albumin–creatinine ratio of 30 to 300 mg/g. Results: The multivariate-adjusted odds ratios of chronic kidney disease and microalbuminuria in participants with the metabolic syndrome compared with participants without the metabolic syndrome were 2.60 (95% CI, 1.68 to 4.03) and 1.89 (CI, 1.34 to 2.67), respectively. Compared with participants with 0 or 1 component of the metabolic syndrome, participants with 2, 3, 4, and 5 components of chronic kidney disease had multivariate-adjusted odds ratios of 2.21 (CI, 1.16 to 4.24), 3.38 (CI, 1.48 to 7.69), 4.23 (CI, 2.06 to 8.63), and 5.85 (CI, 3.11 to 11.0), respectively. The corresponding multivariate-adjusted odds ratios of microalbuminuria for participants with 3, 4, and 5 components were 1.62 (CI, 1.10 to 2.38), 2.45 (CI, 1.55 to 3.85), and 3.19 (CI, 1.96 to 5.19), respectively. Conclusions: These findings suggest that the metabolic syndrome might be an important factor in the cause of chronic kidney disease.