Objective: A five-year follow up of patients with epilepsy to examine the change in their oral health and seizure condition. Basic research design: A prospective observational controlled epidemiologic study under natural treatment settings. Participants: The epilepsy group consisted wholly of patients participating in an epidemiologic survey performed five years previously. The gender- and age-matched control (non-epilepsy) group consisted partly of subjects recovered from the previous study, and partly of new subjects. Interventions: Data pertaining to the disease were collected and a thorough dental examination was performed. Main outcome measures: Indices quantifying oral hygiene, the number and condition of the remaining teeth and periodontium, and the degree of prosthetic treatment were measured. Statistical comparison was performed between the patient and the control group of the present study, and pair wise between the previous and the present survey. Results: The epileptic condition of the patients showed significant improvement upon follow-up, in contrast to a significant deterioration in their oral health as compared to the control group. Concerning oral health, dental indices describing oral hygiene and periodontal condition showed the most pronounced decline. Conclusions: The improvement in the epileptic condition of patients is attributed to changes in treatment strategies. As the epileptic condition and oral health of patients changed in opposite directions, socioeconomic and educational factors appear to play a more important role in the poor oral health of these patients than disease-specific factors (e.g. oral cavity injuries, increased exertion on the teeth, antiepileptic drug effects). Furthermore, the periodontal condition seems to be main factor responsible for the unfavourable dental status. Key words: Epilepsy, oral health, periodontal state