Compounds of nominal compositions Cr1.8Ti0.2O3+delta, Cr1.7Fe0.1Ti0.2O3+delta and Cr1.78Mn0.02Ti0.2O3+delta have been prepared by a co-precipitation method and characterized by X-ray powder diffraction and thermal analyses. The sensor characteristics of these nominal compositions are reported. The sensors fabricated using the powders calcined at 773, 873, 973 and 1273 K were tested for their sensing properties towards ammonia. hydrogen and liquefied petroleum gas (LPG). The influence of calcination temperature and the incorporation of iron and manganese oxides in enhancing the sensitivity are discussed. (C) 2004 Elsevier B.V. All rights reserved.