A polycrystalline sample of gadolinium zirconate (Gd2Zr2O7) was synthesized through a solid-state reaction route (unmilled sample) and then subjected to high-energy ball-milling for 6 hrs and 18 hrs duration (milled samples). Interestingly, elemental analysis of the samples indicates the gradual reduction in the atomic percentage of Gd and Zr cations while significant enhancement in oxygen atomic percentage with the milling process. Rietveld refinement of X-ray diffraction patterns suggests that all samples possess defect fluorite structure and the values of the goodness-of-fit parameter improve from 3.88 for the unmilled sample to 1.85 for 18 hrs milled sample. The diffraction pattern of 18 hrs milled sample showed reflections from the ordered pyrochlore phase. The formation of the disordered fluorite phase is owing to the preparation temperature and the ionic radius ratio, r(Gd3+)/r(Zr4+) = 1. 46. Transmission electron micrographs, and selected area electron diffraction patterns analysis confirm the nanophasic nature of the milled samples, and particle size is found to reduce with increasing milling time. It was found that BET surface area continuously increases from 1.99 m2/g for an un-milled sample to 17.79 m2/g for 18 hrs milled sample. The BET isotherms exhibited type-II hysteresis loop and suggested that all the samples are macroporous with pore width greater than 50 nm.