Purpose : Emphysematous pyelonephritis is a rare, life threatening infection of kidney and the perinephricspace, characterized by the production of gas within the renal parenchyma. The aim of this study is to analyze theclinical and radiologic characteristics of emphysematous pyelonephritis. Materials and Methods : We reviewed 7cases of the emphysematous pyelonephritis. Six patients had plain abdominal radiographs, ultrasonograms andabdominal CT scans. Only one patient had plain radiograph and ultrasonogram. In 5 operated cases, CT findings werecompared with surgical records. Results : Plain radiographs showed characteristic diffuse mottling of gas in renalfossa. On sonogram, intrarenal gas was identified as echogenic foci with dirty shadows. CT scan showedinflammatory mass with gas and fluid levels in adjacent to the kidney. CT findings corresponded relatively wallwith the surgical findings in regard to disease extent. Conclusion : Intrarenal gas in appropriate clinicalsetting is highly specific for emphysematous pyelonephritis. CT is the most sensitive method for demonstrating thedisease extent as well as specific diagnosis.