In the present work, multi-cation-doped (Sr2+-Mg2+) SiAlON ceramics were investigated. MgO and SrO were used in 100:0 and 50:50 molar ratios. The mixture was sintered at 1800 degrees and 1830 degrees C for 1 h in a gas pressure-sintering furnace. The results showed that sintered samples were composed of mainly alpha- and beta-SiAlON phases and small amounts of some Sr-containing phases and SiAlON polytypes. According to Rietveld analysis of X-ray diffraction patterns, Mg is incorporated into the alpha-SiAlON structure. However, the incorporation of Sr is limited.