Novel N-(benzo[d]thiazol-2-ylcarbamoyl)-2-methyl-4-oxoquinazoline-3(4H)-carbothioamide derivatives were synthesized and evaluation of their anticonvulsant effects was done using various models of experimental epilepsy. Initial anticonvulsant activities of the compounds were investigated using intraperitoneal (i.p.) maximal electroshock shock (MES), subcutaneous pentylenetetrazole (scPTZ) seizure models in mice. The quantitative assessment after oral administration in rats showed that the most active was 2-methyl-4-oxo-N-(6-(trifluoromethoxy)benzo[d]thiazol-2-ylcarbamoyl)quinazoline-3(4H)-carbothioamide (SA 24) with ED50 values of 82.5 μmol/kg (MES) and 510.5 μmol/kg (scPTZ). This molecule was more potent than phenytoin and ethosuximide which were used as reference antiepileptic drugs. To explain the possible mechanism for anticonvulsant action, some of the selected active compounds were subjected to GABA (γ-amino butyric acid) assay and AMPA ((S)-2-amino-3-(3-hydroxyl-5-methyl-4-isoxazolyl) propionic acid) induced seizure test.