The polypyrrole-zinc oxide (PPy-ZnO) hybrid sensor doped with different weight ratios of camphor sulphonic acid (CSA) were prepared by spin coating technique. These CSA doped PPy-ZnO hybrids were characterized by field emission scanning electron microscope (FESEM) and fourier transform infrared (FTIR) which proved the formation of polypyrrole, PPy-ZnO and the interaction between polypyrrole – ZnO (PPy-ZnO) hybrid with CSA doping. The gas sensing properties of the PPy-ZnO hybrid films doped with CSA have been studied for oxidizing (NO₂) as well as reducing (H₂S, NH₃, CH₄OH and CH₃OH) gases at room temperature. We demonstrate that CSA doped PPy-ZnO hybrid films are highly selective to NO₂ along with high-sensitivity at low concentration (80% to 100 ppm) and better stability, which suggested that the CSA doped PPy-ZnO hybrid films are potential candidate for NO₂ detection at room temperature.