A novel method which combines laser vaporization of metals with controlled condensation in a diffusion cloud chamber is used to synthesize nanoscale metal oxide and carbide particles (10-20 nm) of homogeneous size and well-defined composition. The following oxides have been synthesized : ZnO, SiO2, Fe2O3, Bi2O3, PdO, NiO, AgO, TeO, Sb2O3, TiO2, ZrO2, Al2O3, CuO, In2O3, SnO, V2O5, and MgO. The microscale structures of the SiO2 and Al2O3 particles exhibit secondary open-structure arrays of interesting weblike matrices with significant volumes of voids in the aggregate structure. These materials may have special applications in catalysis and as reinforcing agents for liquid polymers.