Rett syndrome (RTT) is a progressive neurological disorder characterized by a wide spectrum of phenotypes. Epilepsy is reported to occur in 50-90% of patients with RTT; some develop medically refractory epilepsy. The aim of this study is to investigate the efficacy of levetiracetam (LEV) in drug-resistant patients with RTT. This prospective, pragmatic, open-label study consisted of an 8-week baseline period and a 6-month evaluation period. Efficacy variable was the mean frequency of monthly seizures before, and after 3 and 6 months of treatment with LEV. Eight female patients, aged 7.5-19 years (M12.8+/-5) entered the study. Mean age at epilepsy onset was 25.8+/-14.1 months. All patients showed MeCP2 mutation. Patients had been treated with a mean of 3.4 AEDs (2-7) before LEV. The mean LEV dose was 44.84+/-18.02mg/kg/day. The mean monthly seizure frequency for all types of seizures during the baseline period was 21.3+/-8.1 (range 10-35); after 3 months it was 3.3+/-4.1 (range 0-9) and after 6 months of LEV treatment it was 1.5+/-2 (range 0-4), p<0.0001. The mean follow-up period was 20.2+/-13 months. Mild sleepiness occurred in two patients, one reported intermittent agitation. Levetiracetam appeared effective in our series of drug-resistant RTT patients. All reported a reduction in seizure frequency and consequently a better quality of life.