Recently, impact of binary gas on nanoparticle formation through wire explosion process has been investigated [Materials Letters 2007; 61:1823-1826]. However, the experimental observations seemed to be inconsistent with the explanations. In this work, effect of the ambient gas species on the characteristics of the produced nanoparticles in wire explosion process is investigated to understand the inconsistent experimental observations. Cu wire was exploded in ambiances of Ar, N-2 and their admixtures with different ratios. X-ray diffraction and transmission electron microscopy are used to characterize the as synthesized nanoparticles. Considerable variation in arc plasma formation time and their impact on the characteristics of the produced nanoparticles with ambient gas species are observed. Arc plasma formation is found to be a probable reason for the inconsistent experimental observations with the explanations. (C) 2012 Elsevier B.V. All rights reserved.