The drug taking habits and compliance of 16 epileptic children were studied by means of a questionnaire, "pill" count and serum antiepileptic drug levels (AEDL). The questionnaire method overestimated patients' compliance while, because of the pharmacokinetics of antiepileptic drugs in children, single outpatients' drug levels may be misleading thereby not always reflecting the true degree of compliance. Ten patients (62%) took more than 85% of their medication. Above this level of compliance there was a positive relationship to seizure control. It would appear that drug compliance in epileptic children is as unsatisfactory as it is in adults on whom they largely depend for the administration of their medication.