Development of organic–inorganic nanocomposite scintillators as a new class of scintillators is reviewed. Advantages and shortcomings of polymer-based organic scintillators, i.e. plastic scintillators, are described among the desired properties of scintillators. Development of scintillators by addition of organometallic compounds in the plastic scintillators as an approach to overcome the shortcomings is introduced. In comparison to this approach, nanocomposite scintillators comprising plastic scintillators added with inorganic nanoparticles are introduced. The synthesis methods achieved their properties and their applications are reviewed. Finally, possible strategies for further improvement of the properties of the nanocomposite scintillators are presented.