Twelve patients were identified at an epilepsy center who had medically intractable juvenile myoclonic epilepsy. Significant characterization of this group included the long duration of their epilepsy (averaging 21 years) during which the diagnosis and appropriate treatment was delayed. A high percentage of these patients had asymmetries or focal discharges on scalp EEG (6 of 9 patients). A review of the literature and the findings in these 12 patients lead to the conclusion that juvenile myoclonic epilepsy is not necessarily a benign epilepsy. Alternative therapies, such as epilepsy surgery, may be indicated in such extreme cases.