In order to evaluate potential long-term kidney damage of childhood leukemia and risk factors affecting renal damage, we studied 116 children treated for acute lymphoblastic leukemia (ALL) using the St. Jude Total XI and XIII protocols in 1991-1998. The median follow-up period after the completion of treatment was 35 months. The following parameters were examined: urinalysis, urinary creatinine (Cr), calcium (Ca), phosphorus, beta(2)-Microglobulin, glomerular filtration rate (GFR), tubular phosphorus reabsorption (TPR), and renal function tests. Radiological evaluation included renal ultrasonography (US), and renal scans with DMSA or MAG-3 were performed. Blood chemistry and renal US patients were normal in all patients except two. GFR, TPR, urinary Ca/Cr, beta(2)-microglobulin, and renal scan were abnormal in 19.0%, 16.4%, 13.8%, 6.0%, and 40.5% of patients, respectively. The abnormality rate in GFR was significantly higher in patients<2 years of age. TPR abnormality was found to be significantly higher in patients who did not have G-CSF. An abnormal renal scan was associated with Hb< 10 g/dL, kidney infiltration, or hypertension at presentation and also occurred patients who underwent methotrexate treatment with frequent intervals during the follow-up period. Patients should be followed-up after cessation of therapy with the conventional tests mentioned above. In case of any abnormality, further detailed tests should be performed; renal scan seems to be more predictive for renal damage. (C) 2004 Wiley-Liss, Inc.