A heat dissipation device includes a first heat sink (10), a second heat sink (20), a pair of heat pipes (30) connecting the first heat sink and the second heat sink and a fan assembly (40) located between the first heat sink and the second heat sink. The first heat sink comprises a base (12), a cover (14) and a plurality of heat dissipating fins (16) sandwiched between the base and the cover. The second heat sink comprises a plurality of cooling fins (22). Each heat pipe comprises three portions, respectively orderly sandwiched between the base and the heat dissipating fins, sandwiched between the cover and the heat dissipating fins and thermally extending in the cooling fins.