A 15 years-old girl with no previous history of epilepsy or neurological disease presented three types of epileptic symptoms the same day: 1) clusters of rhythmic myoclonus of the left hemiface; 2) episodes of painful paresthesias of the left arm followed by secondary generalised seizures; 3) episodes of elementary visual hallucinations of the right hemifield. She had several seizures each hour and some were recorded. There were no EEG abnormalities during the facial myoclonus but rapid rhythms were seen during the sensory and visual partial seizures on the right parietal and left occipital lobes. There was no fever and no drowsiness. The CSF tap showed pleocytosis. Serological studies indicated recent mumps. The drugs were initially inefficient. The seizures disappeared after a month. The drugs were stopped after three months and the seizures had not relapsed after a one year's follow-up. Though there were no other sign of encephalitis, we believe that episode of multifocal seizures was due to mumps encephalitis.