On the paths of quantum computation and quantum imaging, light and more specifically photons have a leading role because of the wide range of quantum states that can be produced and controlled almost at will nowadays in laboratories. Among the resources of information carried by photons, quantum entanglement is one of the most important so that it is crucial to control or to be able to characterize the entanglement of quantum states during communication or imaging processes. Besides, though multiple-scattering of classical states of light in disordered media, such as biological tissues or dielectric powders for instance, has been a subject of intense research activity, the propagation of quantum light in random media is still not well understood. In this talk, after an introduction to multiple-scattering of light, I present a random matrix approach used to characterize the high-dimensional entanglement of a photon pair transmitted through a random medium. Using the scattering matrix formalism, I show how to quantify the average amount of entanglement in the transmitted state. The results obtained in the case of a maximally entangled incident state are discussed and I show how the statistics of the disorder impacts the density distribution of the Schmidt eigenvalues that describe the entanglement.