BACKGROUND/AIMS: To evaluate the efficacy of oxcarbazepine (OXC) in the treatment of agitation and aggression in patients with Alzheimer’s disease, vascular dementia or both. METHODS: This is an 8-week, multicenter, randomized, double-blind, placebo-controlled trial carried out independently of the pharmaceutical industry. Changes in the agitation and aggression subscore of the Neuropsychiatric Inventory (NPI) were the primary outcomes. The secondary out- comes were the changes in the caregivers’ total burden scores (measured by the NPI) and changes in the Brief Agitation Rating Scale (BARS). RESULTS: In total, 103 institutionalized patients at 35 sites were randomized to the trial. After 8 weeks, no statistically significant differences were found between the 2 groups for all outcomes. A trend was observed in favor of the OXC group in the reduction in the scores on the BARS (p = 0.07). CONCLUSION: This study found no significant effect of OXC in treatment of agitation and aggression in patients with dementia.