BACKGROUND Chilean women have one of the highest mortality rates from gallstone disease in the world. There is no primary prevention for the disease and the benefits of prophylactic cholecystectomy in high risk groups have not been studied. AIM To analyze the cost and effectiveness of a screening program for gallbladder disease in the Chilean women population. METHODS A decision analytic model is used to compare lifetime cost and effectiveness of standard care with three screening strategies. The first two strategies consider "universal ultrasound screening" for all women 40 years old and laparoscopic cholecystectomy for those with gallstones ("elective intervention") or with calculous > or = 3 cm ("high risk intervention"). The third strategy is based on "selective screening" for obese women. RESULTS The lifetime probability of a 40 years old Chilean woman of dying from gallbladder disease is reduced by 70% in the universal screening/elective intervention, by 63% in the high risk intervention and by 18% in the selective screening strategy. Her lifetime expectancy increases by 5.25, 4.64 and 1.24 months respectively. The incremental cost-effectiveness ratio of each screening strategy is US$ 180, US$ 147 and US$ 481 respectively. CONCLUSION A screening program for gallbladder disease in a high risk population achieves significant benefits at a low incremental cost and acceptable cost-effectiveness.