Abstract: The aim of this study was to evaluate the etiology of pediatric Chronic Kidney Disease (CKD) in a tertiary care hospital in north-west of Iran. Medical records of admitted children with CKD in Children's Hospital of Tabriz from 1999 to 2009 were studied retrospectively. CKD was defined as GFR less than 60 mL min -1 1.73 m2 for more than 3 month. The etiology of CKD was determined by clinical, biological, radiological and histopathological examination. During 10 years 115 children including 61 boys (53%) and 54 girls (47%) were studied. The mean age of patients was 8.1 ±3.53 years (range: 4 months to 14 years). Urological abnormalities were the most common cause of CKD (36.5%) followed by acquired glomerular diseases (23.5%), hereditary nephropathies (21.7%), unknown etiology (9.5%) and systemic diseases (6%). The most common urologic anomaly was vesicoureteral reflux (VUR) that accounted for 24.3% of total etiologies followed by obstructive uropathies. Focal segmental glomerulosclerosis was the most frequent glomerular disease and was responsible for 13.9% of patients. Nephronophtisis, cystinosis, infantile polycystic disease and congenital nephrotic syndrome were the most frequent hereditary nephropathies in a descending order. Frequency of parental consanguinity in patients with hereditary nephropathy was significantly higher than other patients (p = 0.001). High frequency of VUR in present study compared with developed countries necessitates more efforts for improving the management and follow up of urinary tract infections.