Emphysematous cystitis (EC) is a rare severe urinary tract infection characterised by pockets of air in and around the urinary bladder wall caused by gas-forming organisms. Common predisposing factors are chronic infection, immunosuppression, diabetes and neurogenic bladder. The presentation may vary from mild illness to severe life-threatening cystitis. We report two cases of incidental detection of EC diagnosed on imaging for the evaluation of unrelated symptoms. Although asymptomatic, this lethal disease still warrants prompt recognition and treatment with broad-spectrum antibiotics and urinary bladder drainage to prevent severe morbidity and mortality.