This study aims to determine the c auses and pattern of tooth mortality among adult patients visiting the dental clinics of Ajman University of Science and Technology (AUST), Faculty of Dentistry, UAE and compare results with other international studies. The study was also aiming to determine the future preventive measures. Materials & method : Retrospective study design, 1000 files of the adult patients from September 2006 till April 2007 have been selected randomly. Results : Out of 519 patients undergone extraction, 1301 teeth were extracted for different reasons. The results of the study show that the major reason for extraction was caries 40.96% followed by periodontitis 33.7%, 21.1% for the endo-perio. lesions. Patients were commonly from the twenties age group 28.1%. Male patients were in general more than female patients except in the age group (12-30). Minitab 15 was used to statistically analyze the data. Conclusion : Caries was the main reason for tooth loss in AUST dental clinics among all patients, upper molars were the teeth most commonly extracted and the twenties age group was the commonest age group came for extraction. Key words : Dental extraction, Tooth mortality, Tooth loss, cohort study.