Introduction: The rational polytherapy of epilepsy during pregnancy is challenging. VPA represents an old antiepileptic with broad spectrum indications and LEV is relatively new antiepileptic used for the treatment of generalized tonic-clonic and juvenile myoclonic epilepsy and adjunctive therapy for focal seizures. Combination of these two antiepileptics during pregnancy, according to the cohort study (Gašparović at al., 2020), was the most common. Aim: The aim of the present study was to assesse the behavioral performance of the mice whose mothers were treated with combination of VPA and LEV (ratio 1:1) continuously during breeding and whole gestation. Method and result: Two groups of NMRI female mice were formed: group of 8 females treated with combination of LEV in dose of 211mg/kg/day and VPA in dose of 200mg/kg/day and control group of 10 females received corresponding volume of saline. Performed doses correspond to human 1000mg/day for both antiepileptics. All animals were treated subcutaneously into the skin on the back of the neck twice daily. The treatment was started when males and females were paired and continued during whole gestation period till the females gave birth. The locomotor and exploratory activity was investigated in open field test at 45th day of postnatal life and parameters such as horizontal distance, rearing, spatial preferences and grooming. Conclusion: Neurobehavioral performance of tested animals indicate the need for long lasting follow up of behavioural patterns in youngs prenatally treated with antiepileptic combinations. Investigation of the adolescent period is important as much as assessement of early postnatal age.