Effects of plasma etching on mixed /-sialon ceramics with different /-ratiowere investigated. A mix of CF4/O2 in a ratio of 2:1 was chosen as reactive gas. Parameters such as etching time and the material composition were examined. It was shown that -grains exhibit a larger etching rate than the grain boundary glassy phase or the -grains, generating pockets in a range of few µm. The so created surfaces were characterized both by scanning electron microscopy (SEM) and by atomic force microscopy (AFM) in contact mode. These complementary techniques also enabled the determination of the bearing ratio.