Epileptic seizures occur more frequently in multiple sclerosis (MS) patients than in the general population. We evaluated clinical, electroencephalographic (EEG) and magnetic resonance imaging (MRI) findings, as well as EEG-MRI correlations and the response to antiepileptic drugs (AEDs) in 270 consecutive patients with definite MS referred to our Department from 1995 to 2002. Thirteen (4.8%) subjects experienced epileptic seizures. In four cases, seizures manifested within 1-2 years ("early-onset"), and in six cases within 8-23 years ("late-onset") of MS diagnosis. Seizures were usually partial with secondary generalization. Thus, acute symptomatic seizures occurred in three cases. Epilepsy usually appeared late in the course of disease, although a single episode or a cluster of seizures can represent the onset symptom or a relapse of MS. Prognosis of epilepsy during the course of MS is usually good but the choice of AEDs remains a matter of debate.