A heat dissipation device includes a primary heat sink (10) contacting a central processing unit and a secondary heat sink (20) attached on heat-generating electronic components adjacent the central processing unit. The primary heat sink includes a base (12) and a heat-dissipation portion (14) disposed on a middle of the base. The secondary heat sink includes a substrate (22) and a plurality of fin assemblies (24) arranged on the substrate. The base is laid on the substrate with the fin assemblies arranged around the heat-dissipation portion. The primary heat sink is partly superposed on the secondary heat sink with a compact structure. The heat-dissipation portion can simultaneously dissipate heat from the central processing unit and its adjacent heat-generating electronic components.