Nanocrystalline metallic powders and coatings have been synthesized using a millimeter wave driven polyol process. We have been able to prepare powders of single elements, alloys, metastable alloys, composites and coatings. Examples of a few of the metals processed in this study include Fe, Co, Ni, Cu, Ru, Rh, Pt, Au, FePt, FexCo100−x, NiAg and Cu-Ni. The polyol experiment was set up in the millimeter wave processing chamber, the beam was directed into the center of the solution and it was brought to reflux, using the millimeter wave beam as a heat source. Varying the power input easily controlled the rate of reflux.