BACKGROUND: Epidemiological data on characteristics of patients undergoing open or laparoscopic cholecystectomy are limited. In this register study we examined characteristics and mortality of patients who underwent cholecystectomy during hospital stay in Sweden 2000 - 2003. METHODS: Hospital discharge and death certificate data were linked for all patients undergoing cholecystectomy in Sweden from January 1st 2000 through December 31st 2003. Mortality risk was calculated as standardised mortality ratio (SMR) i.e. observed over expected deaths considering age and gender of the background population. RESULTS: During the four years of the study 43072 patients underwent cholecystectomy for benign biliary disease, 31144 (72%) using a laparoscopic technique and 11928 patients (28%) an open procedure (including conversion from laparoscopy). Patients with open cholecystectomy were older than patients with laparoscopic cholecystectomy (59 vs 49 years, p