Abstract: A heat dissipation device includes a heat pipe and a heat sink. The heat pipe includes an evaporator section and a rectangular condenser section extending from one end of the evaporator section and surrounding the evaporator section. The heat sink includes a main body and a plurality of fins extending outwardly from four lateral sides of the main body. The main body defines a groove on an end surface thereof for receiving the evaporator section therein. Each of the fins includes a plate-shaped body and a flange extending perpendicularly from an end of the plate-shaped body. The top flanges cooperatively form a rectangular supporting surface for supporting the condenser section thereon. The supporting surface is lower than the end surface of the main body.