Little is understood of the natural history of dental anxiety. The aim of this study was to examine three-year changes in self-reported dental anxiety among adolescent participants in the Dunedin Multidisciplinary Health and Development Study. Dental anxiety was estimated at ages 15 and 18 by means of the Corah Dental Anxiety Scale (DAS). A DAS score of 13+ defined high dental anxiety. Participants were assigned to one of four dental-anxiety study groups (Chronic, Incident, Remitted, or Never) on the basis of changes in reported level of anxiety from ages 15 to 18. Results are reported for the 691 participants who completed the DAS at both ages. The sample's overall dental anxiety score decreased significantly from age 15 (mean, 8.79) to 18 (8.52) (paired t test, t = 2.37; P < 0.05). The Chronic and Never groups had small negative DAS increments, the Incident group showed a substantial positive increment, and the Remitted group recorded an even larger negative increment. Multivariate analysis showed that the DAS score at age 15 was the sole predictor of the change in DAS score for the Chronic and Remitted groups, and was a co-predictor for the Incident and Never groups. An episodic dental visiting pattern was a strong predictor of a positive change in DAS score for the Incident group; and for the Never group, a higher DMFS score at age 15 predicted a positive change in DAS score at 18, but being female was predictive of a decrement. This study indicates lower stability of dental anxiety in late adolescence than has been reported from other age groups.