An LED heat sink for vehicles includes an injection molded product of a thermally conductive resin composition. The thermally conductive resin composition includes 50 to 90 weight % of a thermoplastic polyester resin having a number average molecular weight of 12,000 to 70,000, and 10 to 50 weight % of a flaked graphite having a fixed carbon content of at least 98 mass %, and an aspect ratio of at least 21, and the thermally conductive resin composition has a specific gravity of 1.4 to 1.7, and an in-plane thermal conductivity of at least 1 W/(m·K).