Levetiracetam was recently approved as adjunctive therapy for partial onset seizures. The authors conducted an open-label trial of levetiracetam in eight patients with chronic myoclonus. Patients were assessed by using the Unified Myoclonus Rating Scale. Levetiracetam was well tolerated. Three of five patients with cortical myoclonus experienced reductions in their myoclonus scores, providing support for a larger, placebo-controlled trial in cortical myoclonus.