Aluminum-silicon foundry alloys in the eutectic region have a small range of freezing, good castability, and good properties. Such alloys are used in many engineering applications like automobile, aeronautical, and aerospace industries. In the present work, aluminum-silicon eutectic samples with silicon of 12-13wt.% were prepared using the stir casting method. The microstructure, hardness, porosity, dendrite grain size, tensile strength, and elongation were studied to see the effect of mechanical mold vibration on this eutectic alloy. An amplitude of 0.5 mm and frequency of 5,10,15,20 and 25 Hz were used for casting the samples with mechanical mold vibration. The results showed that the values of the amplitude and frequencies have a significant effect on the studied properties. A decrease in dendrite grain size by used mechanical mold vibration, at frequencies(5,10,15,20 and 25)Hz the decreased by 15%, 26%, 32%, 42%, and 53%. The hardness was increased by used mechanical mold vibration, at frequencies(5,10,15,20, and 25)Hz the hardness increased by 7%, 16%, 25%, 33%, and 40%. Also, a decrease in porosity by used mechanical mold vibration, at frequencies(5,10,15,20 and 25)Hz the porosity decreased by 35%, 46%, 58%, 69%, and 77%. The increase in tensile strength by used mechanical mold vibration, at frequencies(5,10,15,20 and 25)Hz the increased by 12%, 18%, 25%, 29%, and 36%; and increase in elongation percentage by used mechanical mold vibration, at frequencies(5,10,15,20 and 25)Hz the increased by 14%, 29%, 38%, 52% and 71% respectively.