The increasing availability of synchrotron x-ray sources has stimulated the development of advanced hard x-ray (E P 5 keV) microprobes. It is now possible to achieve intense submicron x-ray beams with a variety of techniques including Fresnel zone plates, Kirkpatrick-Baez mirrors, tapered capillaries and Bragg-Fresnel optics. These synchrotron-based x-ray microprobes can be used for ultra-sensitive elemental detection by x-ray Ñuorescence/absorption and for microdi †raction to identify phase and strain with submicron resolution. Advanced methods for forming microbeams are reviewed and the relative merits of each approach are discussed. The efficient techniques developed for synchrotron beams can also be used to tailor the beam properties from conventional x-ray sources.