A 73-year-old man was admitted to the ICU for anuria. He reported no history of urinary disease. The abdominal roentgenography and two echographies showed an empty urinary bladder, a right ureteral calculus without dilatation of the urinary tract. Computed tomography demonstrated the presence of a left ureteral stone. Bilateral retrograde ureteroscopy and drainage allowed a rapid recovery. When the abdominal roentgenography and echography cannot explain the occurrence of anuria, the computed tomography, or better the helical CT, can demonstrate the presence of otherwise unrecognized calculi.