In a fifteen-year period forty-four cases of perforation of the gallbladder were encountered among 2,807 operations for acute and chronic cholecystitis. These cases are classified as follows: Type i (acute, free perforation), five cases; Type ii (subacute perforation with pericholecystic abscess), twenty-five cases; Type iii (chronic perforation with cholecystoenteric fistula), fourteen cases. The mortality rate was 40 per cent for Type i, 4 per cent for Type ii and zero for Type in. Type i or acute, free perforation of the gallbladder is a rare occurrence carrying a high mortality. It is more common in male patients who may have no previous history of gallbladder disease. Physical signs, fever and leukocytosis may be deceptively mild but should be sufficient to justify a diagnosis of an acute abdomen and a decision to operate without delay. Aspiration of the peritoneal cavity, cholecystostomy and drainage is the procedure of choice. In the absence of severe associated disease early operation limited to this simple, essential procedure should result in a reasonably good prognosis. Type ii or localized perforation with the formation of a pericholecystic abscess is the most common sequence in perforation of the gallbladder. Most of the patients are in the sixth decade and most of them give a history of chronic cholecystitis. The immediate clinical picture may be that of acute, subacute or chronic cholecystitis, depending on the time of perforation and the nature of the abscess. A history of chills and fever is suggestive and a mass is palpable in the right upper quadrant in about half of the cases. Cultures of the abscess are usually positive, with the colon bacillus the most common organism. The usual operative procedure is drainage of the abscess and cholecystostomy, but cholecystectomy is often feasible. Convalescence is surprisingly smooth and the mortality is low. Type iii or chronic perforation of the gallbladder with formation of a cholecystoenteric fistula is an uncommon end stage of chronic gallbladder disease. Most of the patients are in the seventh decade and females predominate. About one-third of the patients are admitted with intestinal obstruction due to a gallstone lodged in the terminal ileum. Slowly developing, incomplete obstruction is characteristic. Recovery is rapid after simple ileotomy and removal of the stone. In the other two-thirds of the patients the fistula is found at operation for chronic cholecystic disease which is usually of many years' duration. Jaundice, chills and fever are common symptoms. Stones are frequently found in the common duct. The duodenum and the colon are the most frequent sites of fistula formation. The results have been excellent after cholecystectomy, closure of the fistula and choledochostomy if indicated. The incidence and mortality of perforation of the gallbladder can be reduced somewhat by a general policy of early operation for acute cholecystitis and perhaps even more by the practice of elective cholecystectomy for all patients presenting the history and findings of chronic cholecystitis. If cholecystostomy is done during an acute episode, it should be followed with cholecystectomy a few months later.