A conductometric H2, NO2, and hydrocarbon gas sensor based on single-crystalline zinc oxide (ZnO) nanobelts has been developed. The nanobelt sensitive layer was deposited using a radio frequency (RF) magnetron sputterer. The microcharacterization study reveals that the nanobelts have a single crystal hexagonal structure with average thickness and width of about 10 and 50nm, respectively. The sensor was exposed to H2, NO2 and propene gases at operating temperatures between 150 degC and 450 degC. The study showed that optimum operating temperatures for the sensor are in the range of 300 degC-400degC for H2, 300 degC-350 degC for NO2, and 350 degC-420 degC for propene sensing