In this course, I will review the different uses of liquid crystals to fabricate nanomaterials and to create specific structures at submicron scales. Three main topics will be discussed.  The fabrication of nanostructured materials with original and tunable optical properties is a major trend in the liquid crystal field. For example, recent progress in the synthesis of mesogenic nanoparticles now allows the self-assembly of monodisperse nanoparticles within large scales. The resulting materials are potentially useful for photonics applications.  The liquid crystal elasticity can also be used to create specific structures or to localize particles in chosen places (for example nanowires between two defined points).  In bulk composites, the presence of anisotropic nanoparticles has two main consequences. The properties of the liquid crystal can be greatly changed by a small amount of doping. Liquid cristallinity can also be used to transfer anisotropic properties of nanoparticles at the macroscopic scale. Each of these topics will be discussed through several examples, after a brief introduction and a rapid presentation of the physics of liquid crystals.