Abstract : The emphysematous cystitis is a rare condition characterized by the presence of air in the wall and/or the bladder lumen. The clinical expression of this cystitis is variable. Some patients complain of abdominal pain or urinary symptoms. Other may present only pneumaturia or be totally asymptomatic. This condition is considered as potentially severe since it can lead to an emphysematous pyelonephritis with septicemia and septic shock. Peritonitis may also occur in case of necrosis and perforation of the bladder wall. However, this negative development can be avoided by a diagnosis and an early treatment, and the emphysematous cystitis become therefore of good prognosis. We are here stating the case of a patient with an emphysematous cystitis with symptoms of pneumaturia and lower urinary tract symptoms.