A heat dissipation device includes a heat sink and a heat pipe extending through the heat sink. The heat sink includes a plurality of fins overlapped with each other. An air passage channel is defined between every two adjacent fins for an airflow flowing therethrough. Each of the fins defines a through hole therein for extension of the heat pipe. Each of the fins includes a main plate and an air guiding member formed on the main plate. The air guiding member includes a curved bar. The curved bar extends slantwise on the main plate to a back side of the heat pipe for guiding the airflow to the back side of the heat pipe.