World Kidney Day (WKD) is intended to raise awareness and increase detection of chronic kidney disease (CKD), but most emphasis is placed on adults rather than children. We examined yield of screening for CKD and hypertension among poor children in Mexico. On WKD (2006, 2007), children (age < 18 years) without known CKD were invited to participate at two screening stations. We measured body mass index (BMI), blood pressure, and serum creatinine, and performed dipstick urinalysis. The Schwartz equation was used to estimate glomerular filtration rate (GFR; reduced GFR defined as < 60 ml/min per 1.73 m(2)). Proteinuria and hematuria were defined by a reading of >or= 1+ protein or blood on dipstick. Hypertension was defined by gender, age, and height-specific norms. In total, 240 children were screened (mean age 8.9 +/- 4.1 years; 44.2% male). Proteinuria and hematuria were detected in 38 (16.1%) and 41 (17.5%), respectively; 15% had BMI > 95th percentile for age. Reduced GFR was detected in four (1.7%) individuals. Systolic hypertension was more prevalent in younger children (age 0-8 years, 19.6%; age 9-13 years, 7.1%; age 14-17 years, 5.3%) suggesting a possible white-coat effect. Hematuria, proteinuria, hypertension and obesity were frequently detected among children in a community based screening program in Mexico. This form of screening might be useful in identifying children with CKD and hypertension in developing nations.