We have retrospectively reviewed the records of children aged >1 month to 16 years who had been referred to the Department of Pediatrics of Prince of Songkla University's Faculty of Medicine, a tertiary referral center in Thailand, between 1982 and 2005 and subsequently diagnosed with chronic kidney disease (CKD). Our aim was to evaluate the prevalence and etiology of CKD in southern Thailand. There were 101 cases of CKD, with one case each diagnosed in 1988, 1989 and 1993, respectively, and 98 cases diagnosed between 1994 and 2005. These latter cases were divided into two 6-year periods: an early period (1994-1999), with 32 cases, and a later period (2000-2005), with 66 cases. The majority of this pediatric population with CKD were male (62/101, 61.4%). The etiologies of CKD were 35 cases of chronic glomerulonephritis (CGN) (34.7%), 29 of genitourinary tract (GU) anomalies (28.7%), nine of systemic lupus erythematosus (SLE) (8.9%), four malignancies (4.0%), four miscellaneous (4.0%) and 19 of unknown causes (18.8%). The patients were divided into age groups of <2 years (20 CKD patients), 2-6 years (15), >6-10 years (22), >10-13 years (20) and >13 years (24). The etiologies of CKD were significantly different in each age group, with GU anomalies and glomerulonephritis being the major causes of CKD in children aged <or=6 years (20/36, 55.6%) and >6 years (40/65, 61.5%), respectively. In conclusion, the incidence of CKD in our university hospital situation was not rare, with the prevalence doubling during the past 6 years, and the etiologies varying by age group.