A 96-year-old woman was diagnosed with colitis in our hospital. Her past history was breast cancer and lung cancer but no diabetes mellitus. She suddenly complained of lower abdominal pain. Abdominal computed tomography (CT) revealed intramural gas in the bladder wall and multiple poor contrasting area in her right kidney, which suggested emphysematous cystitis and acute focal bacterial nephritis. Indwelling urethral catheter was performed for bladder drainage and the treatment with antibiotics started. Urine culture revealed Klebsiella pneumoniae and blood culture was negative. After 3 weeks, the abdominal CT confirmed the decrease of gas within the bladder wall and improvement of contrasting area in the right kidney.