Poly(o-anisidine)-tin oxide (POA-SnO 2) nanocomposites has been investigated for the fabrication of low temperature operative (100 °C) liquefied petroleum gas (LPG) sensor. The POA-SnO 2 nanocomposites have been synthesized through an in situ chemical polymerization of o-anisidine in presence of SnO 2 nanoparticles. The POA-SnO 2 nanocomposite shows better LPG sensing properties than that of pure POA. The nanocomposite with 50 wt. SnO 2 exhibits an excellent LPG sensing characteristics at the operating temperature of 100 C such as higher relative gas response (∼23.47 to 3.4 of LPG), extremely rapid response (∼6 s), fast recovery (∼33 s), good reproducibility, and remarkable selectivity. The application of POA-SnO 2 nanocomposites for fabrication of the LPG sensor was demonstrated. © 2011 American Institute of Physics.