The modification of Si-flakes from coarse acicular to fine fibrous is a common issue in Al-Si alloys casting products. The one of aims of this work is to practice the probability of applying the pulsed electric discharge (PED) to modify the morphology of Si-flakes. In the experiment, the Al-12Si alloy cast in plaster mold was treated with high voltage pulse electric discharge during the solidification. The combined effects of strong pulse electric current and chemical additives of refiner/modifier on solidification structure of eutectic silicon and tensile properties were studied. The experimental results indicated that the eutectic silicon flakes can be fragmentized by high-density pulse electric current. The best tensile properties were obtained when pulse electric discharge was used and combined with a trifle addition of refiner/modifier into the molten metal.