An exemplary heat dissipation device for a portable electronic device includes a heat pipe and a heat dissipating member. The heat pipe includes an evaporator section and a condenser section. The evaporator section is attached to a heat source of the portable electronic device. The heat dissipating member includes a sheath, and a porous heat dissipating layer and a working fluid contained in the sheath. The porous heat dissipating layer defines gaps therein. The working fluid is filled in the gaps. The condenser section of the heat pipe is received in the porous heat dissipating layer and thermally contacts the porous heat dissipating layer.