Zeolites have been utilized widely in industry and in household products, for example, as adsorbents, ion-exchangers and catalysts, and have attracted considerable attention as host materials for various recent nanotechnology applications. The SiAlON ceramics, of which α-SiAlON and β-SiAlON are representative phases, are useful for engineering applications because of their excellent mechanical and chemical properties. This review introduces the author’s contributions to the synthesis and characterization of these Si-based materials.