Solvothermal processes are a powerful route for preparing materials. Different examples are given, either in water as solvent or in non-aqueous solvents such as alcohols, liquid NH 3 and NH 2 NH 2 . This quite new approach for materials synthesis will probably be strongly developed in the near future provided that the role of solvents in the supercritical conditions can be better understood from the chemical reactivity point of view.