The aim of this study was to evaluate the potential of multiphasic multidetector-row CT (MDCT) in the detection and staging of transitional cell carcinomas (TCC) of the upper urinary tract. We performed a retrospective chart review of 39 consecutive patients with 41 histologically verified TCC of the renal pelvis and/or the ureter. The urinary tract was examined using MDCT performing unenhanced and contrast-enhanced scans during the corticomedullary (CMP), nephrographic (NP) and pyelographic phase (PP). Tumors were staged according to the TNM classification. MDCT and histopathological findings were correlated. The attenuation of the lesions was documented in Hounsfield units (HU). In MDCT, all 41 TCC--including two multicentric TCC--were detected. TCC confined to the organ (stage 0a-II) was correctly staged in 28/29 tumors (96.6%). Stage III-IV tumors were correctly staged in 8/12 patients (66.6%). Overall, MDCT was accurate in predicting pathologic TNM stage in 36/41 upper urinary tract TCC (87.8%). There was no significant difference of mean attenuation of TCC between CMP, NP and PP (P > 0.05). MDCT with its high spatial and temporal resolution is an accurate tool for detection TCC of the upper urinary tract, with 87.8% accuracy in predicting its stage.