Traditionally, piezoelectric single crystals have been fabricated mainly by melting or solution growth methods. Recently, however, the Solid State Crystal Growth (SSCG) method has been attracting attention as a promising alternative to conventional methods because of its low acoustic impedance Z₃₃, due to the presence of microscopic pores in the crystal, and easy acoustic matching with living organisms and water. Furthermore, SSCG technology has made it possible to fabricate single crystals with complex chemical compositions and incongruent melting behavior. It also has the potential to dramatically reduce production costs, compared with melt-grown crystals. This paper describes the growth mechanism of the SSCG method, outlines the general features of the production technology, and introduces examples of research on lead-based and non-lead-based piezoelectric single crystals. Among them, the latest research on the properties of Pb(Mg_1/3Nb_2/3)O₃-Pb(Zr,Ti)O₃ (PMN-PZT) single crystals fabricated by SSCG, will be described.