The review presents the state-of-the-art analysis of investigations in the field of a new line of research of photochromism – nanophotochromism. The design, properties, and possible applications of photochromic nanoparticles prepared by different methods with the use of photochromic substances (aggregates, host-guest, and polymer systems, solid nanoparticles) aswell as core-shell photochromic nanostructures based on polymers, silica, quantum dots, doped upconversion nanocrystals, and Ag, Au, etc. nanoparticles have been reviewed.