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.