Oxcarbazepine is indicated for use as monotherapy or adjunctive therapy in the treatment of partial seizures in adults and children >or=4 years of age. The purpose of this retrospective chart review was to assess efficacy and tolerability of oxcarbazepine in children <or=4 years of age. A single-center retrospective chart review of patients <or=4 years old with epilepsy receiving oxcarbazepine between 2001 to 2004 was conducted. Twenty patients (male = 13, female = 7; ages 6-45 months [mean age 22.8 months]) who received oxcarbazepine were identified. Seizure types included partial onset (75%), symptomatic generalized (15%), and other (n = 2, 10%). Oxcarbazepine doses ranged between 14-71 mg/kg/day (mean dose: 36.5 mg/kg/day). Oxcarbazepine was prescribed as monotherapy in 15 patients and as first-line therapy in 73% patients. Overall, 70% experienced a significant reduction in seizures, and 50% became seizure-free while receiving oxcarbazepine. Transient drowsiness was reported in 20% of patients during dose escalation. No adverse events were observed in children <2 years old. The findings from this small series suggest that oxcarbazepine as monotherapy and adjunctive therapy may be effective and well tolerated in pediatric patients <or=4 years of age.