Phenytoin (5,5’-dipenylimidazolidine-2,4-dione) and Thiophenytoin (5,5-diphenyl-2-thioimidazolidine-4-one) are the prime examples of anticonvulsant agent. According to reported procedure, they are synthesized by condensation of benzil and urea in presence of base (30% w/v NaOH) using ethanol as solvent which itself acts as CNS stimulant. Removal of solvent after synthesis is most difficult and non-assured process. Therefore in the present work by application of green chemistry principles thiophenytoins were synthesized by condensation of benzil and sub. aryl thioureas in presence of base and water as green solvent. These compounds were characterized on the basis of its spectral (UV,IR, 1H NMR) data.