A 71-year-old woman with a solitary kidney who developed acute renal failure with anuria secondary to a spontaneous perirenal hematoma is described. Serum creatinine peaked at 335.9 micromol/L and BUN at 26.4 mmol/L, but neither surgery nor dialysis treatment was performed because renal function gradually improved. In this syndrome, first described by Wunderlich in 1856, anuria was not previously reported. Conservative management must always be considered rather than emergency surgery, which usually results in nephrectomy.