Bilateral emphysematous pyelonephritis is an extremely rare, rapidly progressive and life-threatening intrarenal and perirenal infection. It is associated with diabetes mellitus, obstruction of the upper urinary tract and the presence of gas-forming coliform bacteria. As it presents as a severe acute pyelonephritis, a high index of suspicion and computer-tomographic imaging are essential to make the diagnosis. Only immediate combined medical and (bilateral) surgical therapy can reduce the high patient mortality. Postoperatively, computer-tomographic monitoring is recommended to follow the response to therapy.