Comprehensive oral examinations carried out over a period of about 10 years on participants in the Veterans Administration Dental Longitudinal Study were evaluated to identify teeth extracted during this time and to ascertain the apparent reason for these extractions. The study population included 736 dentulous adult males, 49% of whom experienced 1,142 extractions. Caries was judged to be the primary cause of tooth loss, responsible for 33.3% of the teeth extracted. Extractions in preparation for a prosthesis (31.3%) and periodontal disease (18.7%) were the other major causes of tooth loss. Thus, dental caries was the prime cause of tooth extraction in this sample of US male adults, while a second major cause was preparation for a prosthesis which included the extraction of sound teeth and teeth with carious lesions which could have been restored. Periodontal disease was clearly not the major cause of tooth loss and was responsible for only 18.7% of the extractions in this population. The results of this study demonstrate that dental caries is a major problem in adults, leading to greater tooth loss than periodontal disease. A large percentage of the tooth loss in these individuals was clearly preventable. The same emphasis placed upon caries prevention in children should be applied to the adult population.