Primary carcinoma arising in the urothelium of the ureter is rare, accounting for only 1% of all cancers of the upper urinary tract. We describe a case in which primary transitional cell carcinoma of the right ureter was sonographically detected in a 45‐year‐old woman. The mass exhibited tumoral vascularity on power Doppler sonography and spectral analysis. © 2000 John Wiley & Sons, Inc. J Clin Ultrasound 28:361–364, 2000.