It is generally agreed that CT is a good staging method of renal cell carcinoma. However, CT has its ownpitfalls. Herein we reviewed 31 patients with renal cell carcinoma whose CT and pathologic stages were available.CT accurately staged 12 of 14 patients with Robson's stage I (86%), 6 of 8 with stage II (75%), 4 of 4 with stageIIIa (100%), 2 of 3 with stage IIIb (67%), and 1 of 2 with stage IV (50%). Overall staging accuracy of CT was 81%(25 of 31). CT failed to differentiate stage I and stage II in 4 cases. CT also failed to diagnose the microscopiclymph node metastasis in 1 case, and invasion of Gerota's fascia in another case. However CT was satisfactory indifferentiating surgically curable stage I to III from surgically incurable stage IV, and high reliable in thediagnosis of inferior vena caval thrombosis. Therefore it is suggested that CT is highly useful in determining thetreatment plan of renal cell carcinoma.