Abstract: A heat sink having a heat pipe protection mechanism includes a heat pipe, a metallic sleeve and a plurality of heat-dissipating fins. The heat pipe has an evaporating section and a condensing section. The evaporating section is combined with a heat-dissipating base. The metallic sleeve has a closed end and an open end opposite to the closed end. The condensing section is disposed through the open end of the metallic sleeve. Each of the heat-dissipating fins has a through-hole corresponding to the heat pipe. The metallic sleeve having the condensing section disposed therein is fitted in the through-hole. By this arrangement, the condensing section is completely separated from the outside, so that the heat pipe can be protected from suffering damage due to external impacts or getting rusty. Thus, the lifetime of the heat pipe is maintained, and the frequency of repairing the heat sink is reduced.