Emphysematous urinary tract infection is a rare, fulminant complication that is characterized by the presence of gas in the pelvicaliceal system, renal parenchyma, perinephric tissues and retroperitoneum. Surgical resection is usually regarded as the treatment of choice, however several studies have shown the safety and efficacy of conservative management under the correct diagnosis and appropriate antibiotic administration. We herein report on two cases of emphysematous urinary tract infection, pyelonephritis and cystitis infected with ESBL-producing Eschrerichia coli, complicated with diabetic mellitus which were successfully treated with conservative treatment.