Soon after the discovery of high-T_c superconductors, Raman spectroscopy has proved to be an excellent technique for the investigation of low energy elementary excitations in these materials and also for their characterization.  Most studies have concerned the frequencies, line-shapes and intensities of k≈0 phonons, and how these phonon parameters depend on structure, chemical composition, temperature, pressure and the interaction with other elementary excitations.

In this Review, we address our full attention to the phonon Raman scattering of cuprate-based high-T_c superconductors and related materials, emphasizing the unusual aspects of Raman scattering in these materials and the use of Raman scattering as a probe to elucidate the properties of these materials. We will discuss several examples based mainly on our recent studies related to the field of high- T_c superconductors in order to demonstrate useful features of Raman spectroscopy. These include (i) phase identification and phonon assignments among the family of Bi- and Pb-based materials, (ii) doping effects and (iii) direct observation of the insulator-to-metal transition.