A heat dissipation device includes a base, a first fin group located above the base, at least one heat pipe connecting the base and the first fin group and first and second fans located at two opposite sides of the first fin group. Each of the first and second fans is oriented with an acute angle to the base. Outlet and inlet of the first and second fans are oriented towards the base and the first fan produces cooling air to blow towards the first fin group and the base and the second fan draws heated air away from the first fin group and the base.