Chronic kidney disease (CKD) is common in the United States. The estimated prevalence of CKD in US adults was 11.7% +/- 0.8% in 2000, based on the National Health and Nutrition Examination Survey (NHANES). Global estimates for CKD prevalence are less certain, but recent studies in Europe, Australia, and China suggest a high prevalence. The most common risk factors for CKD include diabetes, hypertension, cardiovascular disease, a family history of CKD, and age greater than 60 years. Major outcomes of CKD include progression to kidney failure, development of complications of impaired kidney function, and increased risk for cardiovascular disease. CKD is usually silent until its late stages, thus many patients with CKD are detected only shortly before the onset of symptomatic kidney failure, when there are few opportunities to prevent adverse outcomes. Earlier detection allows for more time for evaluation and treatment but requires explicit testing strategies for asymptomatic individuals at increased risk. In the majority of patients, CKD can be detected with 2 simple tests: a urine test for the detection of proteinuria and a blood test to estimate the glomerular filtration rate (GFR). These 2 tests facilitate detection of CKD by all physicians by allowing for identification of CKD without first requiring determination of its cause. Understanding the strengths and limitations of CKD testing is critical for appropriate implementation of these recommendations. Application of CKD testing in national and international screening and surveillance programs could improve public health related to CKD.