A heat dissipation device includes a first heat sink (10) mounted on one side of a video graphics adapter (VGA) card (70) on which a heat generating componnent is mounted to dissipate heat generated by the heat generating componnent, a second heat sink (10') mounted on an opposite side of the card, a pair of heat pipes (40) independent from and intercrossed with each other and connected between the first and second heat sinks for transferring heat from the first heat sink to the second heat sink, a pair of covers (26) attached on the respective first and second heat sinks to form enclosed channels (15) between the covers and the first and second heat sinks respectively, a pair of fans (22) mounted between the covers and the first and second heat sinks for producing airflow through the channels to improve heat dissipation efficiency of the heat dissipation device.