Networked SnO2 nanowires were uniformly functionalized with Pd nanoparticles via γ-ray radiolysis. The Networked SnO2 nanowires were fabricated through a selective growth method. The sensing properties of the Pd-functionalized SnO2 nanowires were analyzed in terms of their response to NO2 and CO gases. The response time and sensitivity of the sensors were significantly improved for NO2 at lower temperatures by the Pd functionalization. The enhancement in the sensing properties is likely to be due to the spillover effect of the Pd nanoparticles.