Emphysematous cholecystitis, or acute pneumocholecystitis, is an infrequent disease of the gallbladder, characterized by the presence of intraluminal, intramural, or extramural gas; clinical manifestations entirely similar to those of acute cholecystitis; and a picture which is always diagnostic on a plain roentgenogram of the abdomen. The presence of gaseous infection in the liver and bile ducts has been noted in postmortem examinations since the beginning of this century. In 1908 Lobingier (9) published the first surgical description, but the condition was not diagnosed preoperatively until 1931, when Hegner (6) observed a well delineated gas shadow in the gallbladder region during x-ray study (intravenous cholangiography) of a patient who presented with pain in the right hypochondrium and icterus. Only a few cases have since appeared in the medical literature. Heifetz (7), in 1956, reviewed 52 examples, and up to date only 4 more cases have been published (1, 2, 13). In this paper we shall present 7 new cases, which are the first to be reported from Colombia. The major incidence of emphysematous cholecystitis is in the fourth and fifth decades, and the disease is more frequent in males than in females. The clinical picture, as noted above, is the same as that produced by acute infection of the gallbladder without formation of gas. There is acute pain of the colic type in the epigastrium and right upper quadrant, frequently radiating to the back and shoulder, with malaise, fever, and sometimes vomiting. Rarely, there is moderate jaundice. The general condition of the patient may be poor, out of proportion to what might be suspected from the symptomatology, and this disproportion may be the only clue to the clinical diagnosis. It has been observed that some patients give a history of previous painful episodes, which generally correspond to concomitant gallbladder disease. A relatively high incidence of diabetes mellitus has also been noted. This, along with cholelithiasis, could act as a precipitating or complicating factor. The bacteria isolated in the cases investigated have been E. coli, Staphylococcus, Streptococcus (aerobic or anaerobic), and organisms belonging to the Clostridium welchii group. The rôle that these and other microorganisms play as causative agents of the disease is not completely clear, since the same bacteria have been isolated in a large percentage of cases of common emphysematous cholecystitis and in apparently healthy gallbladders (5, 12). Possibly they act only secondarily when their virulence is increased by an obstructive process of the cystic duct, stones or, less frequently, biliary sludge, adhesions, or edema.