Background. The aim of the treatment with antiepileptic drugs (AEDs) is to achieve seizure freedom without causing side effects. Assessment of side effects is difficult. They may start insidiously, the patient may not associate certain complaints with the use of AEDs, or the treating physician does not take enough time to discuss this topic during the limited time of a visit in the outpatient department. We know from clinical trials that side effects occur in a substantial group of patients. We do not know whether we deal with this possible complication in an adequate way in clinical practice.