Thirteen new N-1',N-3'-disubstituted-2'H,3H,5'H-spiro-(2-benzofuran-1,4'-imidazolidine)-2',3,5'-triones were synthesized and their pharmacological activity determined with the objective to better understand their SAR for anticonvulsant activity. The anticonvulsant effects of these compounds were evaluated by standard pentylenetetrazol (scPTZ test) and maximum electroshock seizure (MES test) models in mice. Most of the compounds showed ability to protect against the pentylenetetrazol-induced convulsions. Compound 3o (the N-1'-p-nitrophenyl, N-3'-ethyl derivative) in the N-1'-aryl, N-3'-alkyl disubstituted series exhibited maximum activity with ED(50) of 41.8 mg/kg in scPTZ convulsion model.