Gas sensor based on nanostrutured pure SnO2 and Zn doped SnO2 thin films has been synthesized by using spray pyrolysis technique and evaluated for NO2 gas sensing (Gas response=S ~ 1480) at opearating temperature 150 oC with 100 ppm. Sensor structure showed the short response and recovery times 3 and 10 s, respectively. The nanostrutured pure SnO2 and Zn doped SnO2 thin films were used as potential gas sensing material for their stability in thermal and chemical atmospheres. Structural, surface morphology, elemental composition, microstructural, optical and NO2 gas sensing performance of different vol % of Zn (3-7%) were studied and reported. Prepared thin films were characterized by different analytical techniques. The results are discussed and interpreted.