Gallbladder carcinoma is the most common malignancy of the biliary tract in Korea and known to be more common in East Asia and Latin America than in Europe and North America. However, their exact histopathological characteristics and carcinogenesis are not well-elucidated. A total of 71 cases of gallbladder carcinomas, two cases of gallbladder dysplasia and 20 cases of gallbladder adenoma were immunohistochemically studied to evaluate the expression of c-erb-B2 and p53 proteins in the light of their relationship with various prognostic factors. Thirty-three gallbladder carcinomas (46.5%) showed positive staining for c-erb-B2, but none of the dysplasia and adenoma were positive (p<0.05). c-erb-B2 was stained in the cell membrane of the cancer cells. Adjacent normal mucosa was negative for c-erb-B2 staining. Forty-eight gallbladder carcinomas (67.6%) showed positive staining in the nucleus for p53 protein. None of the cases with dysplasia, adenoma, and normal mucosa stained positive for p53 protein. There was no significant correlation between c-erb-B2 and p53 expression and age, gender, histological tumor grade, and tumor stage. In the multivariate analysis, tumor stage approached statistical significance (p=0.05), but c-erb-B2 and p53 expression was not significant (p=0.14 and p=0.29, respectively). The mean survival periods of the c-erb-B2 positive and negative groups were 26 months and 52 months, respectively (p=0.02). However, the mean survival periods of the p53 protein positive and negative patients were 34 months and 35 months, respectively (p=0.45). In conclusion, our results suggest that c-erb-B2 and p53 protein expression is strongly associated with neoplastic progression in gallbladder carcinomas, and that c-erb-B2 expression identifies patients with a worse prognosis.