Chronic kidney disease (CKD) is common in Japan and worldwide. The estimated prevalence of CKD in Japanese adults was 10.6% in 2005, based on the survey conducted by the Japanese Society of Nephrology. The most common risk factors for CKD include diabetes, hypertension and cardiovascular disease. Major outcomes of CKD include progression to kidney failure 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. Understanding the strengths and limitations of CKD testing and risk factors of CKD is critical for appropriate management of CKD patients. The goal of this paper is to discuss CKD testing and early detection in clinical practice and its application to public health initiatives, with attention to limitations and appropriate interpretation.