A heat dissipation device includes a heat sink assembly, a fan holder and a fan mounted in the fan holder. The heat sink assembly includes a heat spreader for contacting with a heat-generating electronic component, and two fin assemblies thermally connecting with the heat spreader and sandwiching the fan therebetween. Each fin assembly defines cutouts at opposite ends thereof. The fan holder includes a top plate and a pair of vertical, downward-extending baffle walls. A pair of clamping arms extends from each baffle wall and inserted into the cutouts of the fin assemblies. Screws extend through the top plate to engage in holes defined in the fin assemblies and communicating with the cutouts. A vaulted operating plate is formed by the top plate for a user to grip to conveniently transport the heat dissipation device.