Abstract Renal radionuclide scans of 102 patients with varying levels of renal insufficiency were reviewed. Three scan grades were defined in terms of ability to determine kidney location, size, shape, pathology, and overall definition. The scan grades were then correlated with the level of serum creatinine and blood urea nitrogen. It was found that the ability to obtain information from the scan can be predicted by knowing these levels. A good scan can be obtained with creatinine levels of 2.4 mg/100 ml or blood urea nitrogen levels of 39 mg/100 ml. The serum creatinine level appears to be the more reliable of the two indicators.