Neodymium oxide (Nd2O3) powder with closed packed hexagonal (cph) crystal structure was synthesized from the elemental neodymium (Nd) using soft chemistry route. The hydrated neodymium nitrate was produced by reacting metallic Nd with nitric acid. At 546 °C, the hydrated neodymium nitrate was thermally transformed to body centered cubic (bcc) Nd2O3 in four-stage thermodynamic reactions. The bcc-Nd2O3 was subsequently transformed to cph-Nd2O3 at 1037 °C. A crystallite size of ~ 50 nm was attainable in the process. It was observed that the degree of crystallinity of the powder was increased with longer exposure time (> 30 min) at 1037 °C. In DSC/TGA studies, five endothermic peaks were observed at different temperatures. During XRD evaluations, it was elaborated that each peak corresponded to certain phase transformation, i.e., Nd (OH)2·NO3 monoclinic (at 160 °C), Nd(OH)3 cph (at 315 °C), Nd2O fcc (at 500 °C), Nd2O3 bcc (at 590 °C), and Nd2O3 cph (at 1050 °C). The FTIR evaluation further validated the findings. The grain size and cph structure of the final product were also verified by TEM study.