The reduction of cobalt, nickel, copper, zinc and aluminum nitrates by formaldehyde, ethylene glycol and glycerol under hydrothermal conditions at temperatures of 220–320⁰C was studied. It is shown that the metal carboxylates (oxalates, formates) can be obtained at temperatures below 240⁰C, while the oxides and metal carbonates form at higher temperatures. The reduction of copper nitrate formed a metallic powder under these conditions. Under certain conditions metallic cobalt and nickel can be obtained as well. Calcination samples received at temperatures up to 240⁰C, at 500⁰C leads to formation of nano-powders of metal oxides with an average size of particles about 30–60 nanometers.