Introduction: gallbladder adenomas are infrequent neoplasms whose relation to adenocarcinoma is not well understood. It has been suggested that adenomas and adenocarcinomas follow different molecular pathways. Material and methods: this is a comparative, cross-sectional study in which we compared p53 and D1 cyclin expression in adenomas and adenocarcinomas of the gallbladder. Results: we included 12 cases in each group. Expression of p53 occurred in 83.3% of adenocarcinomas and in 16.6% of adenomas (p = 0.003). D1 cyclin was expressed in a similar number of adenomas and adenocarcinomas. Conclusion: our results support the hypothesis that p53 is an important step in the pathogenesis of adenocarcinomas but not of adenomas of the gallbladder. D1 cyclin is apparently a common pathway involved in the genesis of both tumors. Copyright © 2007 Arán Ediciones, S. L.