A series of bicyclic derivatives based on 5,5-diphenylhydantoin (DPH) and/or 5-arylidene-hydantoin skeletons (BZH) are discussed as potential anticonvulsants. In preliminary pharmacological tests a few of these agents showed some anticonvulsant activities, like the parent DPH. The electronic parameters (molecular electrostatic potential, MEP, and dipole moment orientation) for the DPH molecule used as a model differed significantly from those calculated for the bicyclic molecules. These parameters were derived from semiempirical quantum chemistry calculations applying the PM3 method.