EMPHYSEMATOUS cholecystitis is a rare form of acute, usually gangrenous, cholecystitis caused by gas-forming organisms and characterized radiologically by the presence of gas within the gallbladder. There may be gas within the wall of the gallbladder as well as in the pericholecystic area. This clinical entity has been reported in the medical literature under such names as gas in the gallbladder, gaseous cholecystitis, pyopneumocholecystitis, pneumocholecystitis, gas phlegmon of the gallbladder, cholecystitis emphysematosa, and gangrenous cholecystitis. Emphysematous cholecystitis is the terminology usually used. It is the purpose of this paper to report on 105 cases—four new cases together with a brief review of 101 cases found in the world literature since 1901. Pathogenesis, diagnosis, and treatment will be discussed. History In 1901, Stolz1 reported three cases discovered incidentally at autopsy in which gas was present in the gallbladder and bile ducts. It is not certain that these were true cases