This study investigated the 18-month incidence of tooth loss in a random sample of 451 dentate noninstitutionalized Iowans aged 65 and older residing in two rural counties. They had a mean of 19.0 teeth at baseline and lost an average of 0.4 teeth during the subsequent 18 months. Twenty-one per cent of the population lost at least one tooth. Four people had all their teeth extracted. Of the teeth present at baseline, 1.9 per cent subsequently were extracted. The highest incidence of tooth loss occurred among mandibular molars (3.7 per cent), followed by maxillary premolars and canines (3.1 per cent each). The best predictors of tooth loss were previous coronal and root caries.