mphysematous pyelonephritis (EPN) is a rare, but severe and life-threatening infectious disease in the kidney. We conducted a retrospective study and enrolled all EPN patients from Taipei Veteran Hospital over the past decade. We identified 32 CT–confirmed EPN patients. Demographic analysis showed female individuals are prone to develop EPN, and up to 78.1 % of the cases with EPN have underlying diabetes mellitus. And the most common causative organism areE coli (50%). In this cohort, the mortality rate was 12.5%(n=4/32), 18.75% of patient (n=6/32) received nephrectomy and 28.13% received only percutaneous drainage with antibiotics. There are four classifications of EPN based on radiological findings, in our cohort, there was 0% of class 1, 40.6% of class 2, 21.88% of class 3A, 28.13% of class 3B and 9.38% of class 4, however we cannot find association between EPN image classifications and advanced renal failure rate or mortality rate. The results from the current study suggests early diagnosis and interventionare the keys to achieve a successful treatment in EPN.