Emphysematous urinary tract infections (UTIs) are lower or upper UTIs associated with gas formation. Emphysematous pyelonephritis (EPN) is a rare disease but is highly prevalent in patients with diabetes and even higher among female patients with diabetes. Earlier, the mortality rate of EPN was 60%–80%, but now, it has been reduced to 20% to 25% due to the availability of good antimicrobial agents and timely treatment. Our objective of this article is to elucidate the pathogenesis of EPN including gas-forming mechanism; discuss clinical features, radiological classification, and prognostic factors; in addition, compare the modalities of management of EPN and outcome among the various radiological classes.