Dental caries and periodontal disease are described as the main etiologic factors for tooth loss worldwide. This is the first epidemiologic study evaluating the reasons for tooth extraction in Costa Rica. Objectives: to determine the main reasons and to report the patterns for tooth extraction in the population under study. Materials and methods: all patients who where attended at the School of Dentistry at the University of Costa Rica between the years 2007 and the 2009 and that had the required information in their personal files were included. Each tooth extraction was classified in one of eight categories according to the reason for extraction and variables such as dental piece, sex and age of the patient were analyzed. Results: Women represented 52% of the total 2618 tooth extractions included. The average age was 36, 29±16,1. Dental caries was the main reason in 50% of the cases, periodontal disease in 17.8% and third molars in 17%. Women had their teeth extracted for elective treatments more than men, whereas men’s extractions were more related with disease reasons. For subjects over 50 years of age, periodontal disease became the main reason for extraction. Conclusion: Efforts directed at reducing the rate of dental extractions by disease must focus on further educating the Costa Rican population on dental caries and periodontal disease, and future studies should monitor the effect of these interventions through time.