Thailand is a developing country in Southeast Asia. It has a population of 64 million and a gross per capita income of approximately US $2200 per year. At present, there are no epidemiologic studies of the prevalence of early-stage chronic kidney disease (CKD) in Thailand. Extrapolating from the NKF/DOQI guideline1, approximately 4.2% of 20-year-old or older Thais (about 2.7 million) might have decreased glomerular filtration below 60 mL/min (stage 3 CKD).