Abstract: The present invention relates to hybrid wicking materials for use in high performance heat pipes and other fields where a bi-modal distribution of pore sizes offers advantages over a homogeneous monolithic porous structure. In one aspect, the invention provides a wicking material for use in heat pipes. This wick is comprised of sintered metal powder formed on a foam, felt, screen or mesh metal substrate. A fine pore structure is formed by the metal powder while the substrate is comprised of large pores. The large pores are several times, preferably five times to several orders of magnitude larger in size than the small pores. The sintered powder metal and the metal substrate may be made of nickel, copper, molybdenum, niobium, aluminium, iron, cobalt, titanium and alloys based on these metals, and combinations thereof.