Background: The aim of this study was to investigate whether planning a dental appointment is a predictor of actual dental visits over a one-year period when controlling for past attendance, demographic factors, and dental health beliefs. In addition, the planning–attendance association was explored to determine whether dental anxiety and educational status moderated this relationship. Methods: A total of N = 1,422 adults with a mean age of M = 44.4 (SD = 11.0) years and resident in Iran participated in a prospective study over a one-year period. The primary outcome was self-reported dental appointment attendance at one-year follow-up, which was validated using clinical records. Action planning, coping planning, health beliefs, age, dental insurance, income, dental health status, dental anxiety, and years of education were assessed at baseline by self-report questionnaire. Data were analysed using multivariate logistic regression. Results: Action planning and coping planning were significantly associated with dental appointment attendance at one-year follow-up. Planning a dental appointment was more predictive of dental appointment attendance for people with higher levels of education and lower dental anxiety. Conclusions: The findings of this study suggest that implementation of the behaviour change technique planning into routine dental practice may have the potential to increase dental appointment attendance rates.