The objective of this study was to determine whether levetiracetam warrants further investigation as a treatment of essential tremor (ET). The authors conducted a 4 -week, open label trial of levetiracetam (Keppra, UCB Pharmaceuticals) in 10 patients diagnosed with ET. Patients were assessed with the complete Tremor Rating Scale (TRS), global impression measures, and adverse events at baseline, after 2 weeks low-dose 500 mg bid and at 4 weeks high-dose 1500 mg bid. All 10 subjects (mean age, 68.6 +/- 7.4 years; seven men, 9 with a positive family history of ET) completed the trial. The TRS observed tremor section modestly improved in 8 subjects (P <0.01). The TRS writing section, water pouring section, and activities of daily living section did not change, and visual analog scores did not change. Subjects rated themselves as "much improved" (n=3), moderately improved (n=1), unchanged (n=1), and mildly worse (n=5). Adverse events included dizziness (n=2), sedation (n=1), and nervousness (n=1). Levetiracetam was well tolerated but failed to improve tremor consistently in this small trial.