Objetive: This article corresponds to a descriptive cross sectional study, which aims to determine the prevalence of primary odontogenic tumors in population attending Hospital Base Valdivia, during a period of 20 years (1989-2008), based on the WHO's 2005 new classification of tumors. Methodology: 2,078 reports of biopsies for lesions oral cavity from Pathology Service Hospital Valdivia Base, between January 1989 and December 2008 were reviewed. The presence of an histologically confirmed diagnosis in the patient's chart and readability of it were considered as inclusion criteria. The variables analyzed included age, gender, histological diagnosis tumor type and location of this area. The collected data was tabulated in database spreadsheet for subsequent statistical analysis. Results: Of the 2,078 biopsies of oral territory, 31 correspond to tumors odontogenic, representing 1.5% of all biopsied lesions territory oral. A malignant lesion was found and corresponds to ameloblastic carcinoma infiltrating. The most frequent lesion corresponded to odontogenic keratocyst tumours (41.9%), followed by ameloblastoma (22.6%), and finally odontoma (16.1%). The average presentation age is 35.7 years. The most common area of presentation is the mandibular molar area (54.8%). Conclusion: Odontogenic tumors are of low prevalence in Hospital Base Valdivia between 1989 to 2008. It's more often in men, no gender predilection, being the most prevalent lesion tumor odontogenic keratocysts.