We studied prospectively 474 cases (83% female with a female:male ratio of 5:1) of gallbladder carcinoma diagnosed in a period of 7 years. Twenty two percent of patients were younger than 50 years old. Ninety percent of tumors were adenocarcinomas. In 1987, 45% of cases were diagnosed in metastases compared to 1993, when only 10% of tumors were diagnosed in such histological material. Thirty four percent of tumors were not macroscopically identified; all these inapparent tumors were advanced in 1987, whereas 53% were incipient in 1993. Moreover, inapparent tumors had a significantly lower degree of gallbladder wall infiltration and higher degree of differentiation. Well differentiated tumors had a lesser degree of wall infiltration. It is concluded that the careful histopathological study of gallbladder cancer has allowed a thorough knowledge of the natural history and clinical presentation of gallbladder carcinoma.