Interstitial titanium-chromium oxynitrides in the solid solution series Ti1-zCrz(OxNy) (z = 0.2, 0.4, 0.5, 0.6, 0.8) have been obtained by ammonolysis of the TiO2/Cr2O3 precursors resulting from the coprecipitation method. The precursors and the resulting oxynitrides were characterized by auger electron spectroscopy, X-ray diffraction analysis, electron probe micro-analysis, transmission electron microscopy, and BET surface area techniques. Compounds in the Ti1-zCrz(OxNy) series are prepared as single phases by nitridation at 1073 K for 8 h. The as-synthesized oxynitride powders contain only Ti1-zCrz(OxNy) with cubic structure and the particle size is in the nanometer scale.