A mouse model of repeated social defeat (nonaggressive male mouse repeatedly defeated by aggressive counterparts) was used. The results showed that acute treatment with felbamate, an antiepileptic drug modulating glutamatergic neurotransmission, reduced hypolocomotion in an open field induced by repeated social conflict. The same stress procedure resulted in increased release of corticosterone and dopamine. Felbamate decreased noradrenaline concentrations and inhibited stress-induced rise in corticosterone and dopamine. It is suggested that modulation of stress hormone release may be induced by the action of felbamate on glutamate neurotransmission, and neuroendocrine changes could contribute to behavioural effects of the drug.