Presented article is focused on heat transfer in injection mold, which is designated for plastic parts production. As experimental part was selected two components injection mold with hybrid cooling. Molds cooling system was in two variants: conventional and conformal cooling. In subsequence three variants of cooling were simulated. First variant contained conventional cooling system manufactured by drilling technology. Second variant was designed with conformal cooling system which copies shape of the molding. Third variant consisted of conventional and conformal cooling combined. Simulation procedure was performed in simulation software ANSYS. Temperature presets for injected molding was set according to used material Makrolon 2805. Heat transfer between individual parts of mold was evaluated using individual probes.