Gallbladder cancer is the most common cancer in the Chilean female population. A prospective histological mapping of cholecystectomy pieces allowed the detection of 37 tumors not evident to the surgeon. Tumoral invasion engaged the mucous membrane in 7, the muscular layer in 8, the subserous layer in 12, the serous membrane in 5 and the surrounding adipose tissue of the gallbladder in 5 cases. 18 pts were reoperated on for resective oncological surgery. In 5 of these cases the ganglia, and in 6 the hepatic tissue behind the gallbladder were involved. Actuarial survival at 38 months was 48% (10 pts have died by the time of this publication). The prognosis of the disease was directly related to histological differentiation and to the degree of tumoral invasion. Gallbladder cancer has a poor prognosis even if the surgeon has no suspicion of the disease and a simple cholecystectomy is by no means a healing therapy.