Emphysematous cystitis is a rare lower urinary tract infection. Patients with diabetes mellitus, neurogenic bladder, and recurrent urinary tract infection are generally at higher risk of this disease. A 71-year-old woman with neurogenic bladder was referred from the internal medicine department because of urinary retention. Abdominal radiography and computed tomographic (CT) scanning revealed a characteristic accumulation of air in the wall and lumen of the urinary bladder. Emphysematous cystitis was improved by antibiotic therapy and urinary drainage. CT scan was a sensitive method for detecting early signs and confirming the diagnosis.