Seizures are a common neurologic symptom of tuberous sclerosis complex. The use of levetiracetam as adjunctive antiepileptic therapy was assessed in 20 patients with tuberous sclerosis complex aged 2 to 19 years. In this retrospective evaluation, 40% of patients treated with levetiracetam achieved a seizure reduction of more than 50%. Levetiracetam was generally well tolerated, and adverse events were relatively uncommon in patients who responded to treatment. The most commonly reported adverse events were behavioral problems. Unstable gait, insomnia, poor appetite, and increased seizure frequency were also reported. Based on these results, the use of levetiracetam as adjunctive antiepileptic therapy can reduce seizure frequency in patients with tuberous sclerosis complex. (J Child Neurol 2006;21:53-57).