High pressure die casting (HPDC) is widely used for manufacturing aluminum parts in automotive industry. In high pressure die casting mold, chill vents are used to allow residual air and gases to exhaust out from the mold cavity. The objective of this paper is to design and develop a bi- metallic chill vent for high pressure die casting using copper alloy material having high thermal conductivity, coated with steel layer on the surface. Transient thermal analysis was carried out using ANSYS software, and temperature distribution was compared with bimetallic and tool steel chill vents. The results show a faster extraction of heat in bi-metallic chill vent than that with steel. This paper also presents the effect of varying internal diameter of cooling channel in chill vent cooling.