A case of emphysematous pyelonephritis is presented. A 66-year-old woman with diabetes mellitus was hospitalized for sudden pyrexia and left abdominal pain on January 13, 1987. She had shown preshock, pre-disseminated intravascular coagulation, hyperglycemia and renal dysfunction. Plain X-ray films of the abdomen and abdominal computer tomographic scanning showed a gas shadow in the left kidney. Retrograde pyelography demonstrated the left complete ureteral obstruction. A diagnosis was made of emphysematous pyelonephritis associated with diabetes mellitus and ureteral obstruction. Left nephrectomy was performed on January 17, 1987, and the pus obtained from the kidney yielded E. coli. After the operation, she has been doing well with diabetes mellitus under good control without insulin therapy. Thirty two cases of emphysematous pyelonephritis in the Japanese literature including our case are reviewed.