A novel Russian medicine dimephosphonum at its therapeutic doses of 50mg/kg and 100mg/kg showed anti-seizure activity on models of primary generalized seizures caused by corazolum or by maximal electroshock in rats and mice. Dimephosphonum prevented death of rats and mice in both seizure models like reference preparations phenazepam, valproic acid, and levetiracetam. The effects of dimephosphonum were less pronounced compared to phenazepam or valproic acid, but were comparable to those of levetiracetam.