Porous nanosized Sb doped SnO2 powder with different Sb concentrations has been synthesized by a low cost nonaqueous sol-gel method. Thick films of the synthesized material show an extremely high response of 4316% to few parts per million level of ammonia at room temperature with good stability for a long period of time. The adsorption of ammonia on the sensor surface obeys Elovich equation and the reaction kinetics is of first order with a rate constant as large as 0.09235 s(-1). (C) 2010 Elsevier B.V. All rights reserved.