The sensors based on the semiconductor CdS nanoparticles were fabricated in spray technology. The properties of the sensors response to SO2, H2S, NH3, NO2, water vapor and some organic solvent vapors were studied systematically. The sensors exhibited a good response to SO2, H2S and NH3 at room temperature. The sensor based on CdS prepared with Na2S at 353 K displayed a linear response to NH3 from 0.3 to 6.0% and to SO2 from 0.5 to 1.7%. The sensor based on CdS prepared with H2S at 353 K displayed a linear response to NH3 from 0.08 to 1.1% and to SO2 from 0.25 to 1.5%. All the sensor response and recovery times were less than 54 s and 70 s respectively. Temperature and operating voltage significantly affected the response of the sensor. (C) 2013 Elsevier Ltd. All rights reserved.