Cyclic antidepressant treatment in adults is reported to increase caries activity. The aim of this study has been to evaluate if such treatment also causes a higher frequency of dental caries in children. Children with enuresis treated with tricyclic antidepressants (AD) were compared to matched controls and to enuretic children without antidepressant treatment. Dental records and radiographs were examined concerning caries activity. During the treatment period the mean caries activity was higher in the group of children treated with AD for 1 month or longer compared to both controls and enuretics without pharmacological treatment. These findings show the need to send the child to a dentist for optimal caries prophylaxis at the start of antidepressant treatment.