: In the present study, in-situ cast A356-TiC composites with different reinforcement contents were synthesized by addition of activated mixtures of Ti and C powders to A356 melts and their properties were characterized. First, stoichiometric mixture of Ti and carbon powders were milled at room temperature under argon atmosphere for different times using a high intensity planetary ball mill. The ball-to-powder weight ratio was kept at 40:1 and milling time varied from 1 to 5 hours. The as-milled powders were then characterized using XRD and SEM techniques. DTA analyses were also carried out to investigate temperature-induced phase transformation of the as-milled powders. XRD results showed that TiC particles were formed after about 4 hr of milling. It was concluded that ignition of the reaction for TiC formation occurred at a milling time between 3 and 4 hr. Result of DTA analyses indicated that the ignition temperature of exothermic reaction decreased with increasing the milling time to a temperature below 500 °C. Consequently, the 3 hr activated mixture was incorporated into A356 alloy melts via vortex method to produce A356-TiC slurries of different reinforcement content. The composite slurries were cast in a steel die and subsequently hot pressed to close off their porosities. Microstructural characterizations were performed by optical microscopy and SEM. Tensile, hardness and wear tests were carried out in order to identify mechanical properties of the composite and monolithic samples. The results of microstructural studies revealed the formation and uniform distribution of TiC particles in the matrix as well as grain refinement of the matrix and low porosities in the composite specimens. Results of mechanical tests showed that addition of the activated mixture of Ti and C powders led to improvement in the yield strength, ultimate tensile strength and hardness. It was indicated that the fabrication process and the particle content were the most effective factors in?uencing the mechanical properties. In comparison with the monolithic A356 samples processed by stir casting, the tensile strength of A356-3wt.% TiC composite increased by 50% and reached to 190 MPa . Hardness of the same sample increased to 118 BHN from 80 BHN. The highest wear resistance was achieved for the cast A356-1wt%TiC composite. Keywords: In-situ A356-TiC composite, Mechanical activation, Vortex casting, Mechanical properties, Wear resistance