Herein, we demonstrated the oriented attachment(OA) driven formation and characterization of Gd_2O_3 nanorods. The nanorods were synthesized via a surfactant free, inexpensive hydrothermal route and considering ~30 nm nanoparticles as the seed. While maintaining a cubic phase throughout the process, complete transformation of Gd_2O_3 nanoparticles to nanorods was found to occur at an elevated temperature(~180 oC) of the hydrothermal reaction. The elongated Gd_2O_3 nanostructures, as revealed from transmission electron microscopic imaging, possessed an average diameter of ~33 nm and an approximate length of 172 nm. From the kinetics of OA process, the activation energy of formation was estimated to be ~25 k J/mole. The existence of defect mediated radiative emission was ascertained from the asymmetric broadening of luminescence spectra. The defect emission arising from the Gd_2O_3 nanorods was nearly 1.4 times stronger than that of nanoparticles. The morphological evolution and growth kinetics were discussed along with the luminescence and electron paramagnetic resonance features. Herein, we demonstrated the oriented attachment (OA) driven formation and characterization of Gd 2 O 3 nanorods. The nanorods were synthesized via a surfactant free, inexpensive hydrothermal route and considering ~ 30 nm nanoparticles as the seed. While maintaining a cubic phase throughout the process, complete transformation of Gd 2 O 3 nanoparticles to nanorods was found to occur at elevated temperatures (~ 180 oC) of the hydrothermal reaction. The elongated Gd 2 O 3 nanostructures, as revealed from transmission electron microscopic imaging, possessed an average diameter of ~ 33 nm and an approximate length of 172 nm. From the kinetics of OA process, the activation energy of formation was estimated to be ~ 25 k J / mole. The existence of defect mediated radiative emission was ascertained from the asymmetric broadening of luminescence spectra. The defect emission arising from the Gd_2O_3 nanorods was nearly 1.4 times stronger than that of nanoparticles. The morphological evolution and growth k inetics were discussed along with the luminescence and electron paramagnetic resonance features.