A 16-year-old girl diagnosed as having type 1 diabetes mellitus and oliguric acute renal failure which developed 24 hours after computerized tomography with the infusion of contrast material is presented. She required short-term hemodialysis and in two weeks her renal functions returned to normal. All the findings in this high-risk patient suggest the development of contrast material-induced nephropathy. We propose that there should be adequate hydration before radiocontrast material studies are performed on diabetic patients.