Information on mortality after cholecystectomy in defined populations is limited. In this study we examined the case fatality rates and mortality ratios, based on register data. Hospital discharge and death certificate data were linked for all patients undergoing cholecystectomy in Sweden in 1987-99. Mortality risk was calculated as the standardized mortality ratio (SMR). From 1 January 1987 to 1 December 1999, 123,099 patients underwent cholecystectomy for acute or chronic gallbladder disease. Between 1987-91 and 1995-99, the incidence of cholecystectomy increased by 13%, median age of patients decreased and the proportion of women increased. From 1995 to 1999, 32% of all cholecystectomies were completed as open cholecystectomy. During this period, 82% of patients aged 70 years or older with acute gallstone disease had an open cholecystectomy. For patients with chronic gallstone disease, the proportion was 43%. Postoperative crude mortality within 30 days for all patients was 0.4%. Patients with acalculous gallbladder disease had double the mortality risk compared with patients with calculous disease, and patients with acute cholecystitis had double the risk compared with patients with chronic disease. High age, previous hospital admission for conditions other than gallbladder disease, and cholecystectomy completed as an open procedure increased the risk, whereas gender and calendar year did not significantly affect the mortality risk. Biliary tract diseases accounted for 61% of all postoperative deaths, whereas 26% were due to cardiovascular diseases. During the 1990s, cholecystectomy incidence increased, whereas postoperative mortality risk remained unchanged. In order to further reduce the mortality risk, particular attention should be paid to elderly and frail patients and to patients with acalculous gallbladder disease.