Single phase intermetallic RENi₂Si₂ (RE = Y, La) nanoparticles were successfully prepared at as low as 600°C in molten LiCl–CaH₂ system. The BET surface areas were 40.0 m²/g and 14.4 m²/g corresponding to the particle sizes of 26.0 nm and 65.5 nm for YNi₂Si₂ and LaNi₂Si₂, respectively. The improved surface areas are much higher than those prepared by a conventional arc-melting of <2 m²/g. The novel preparation approach presented in this study is a simple scalable chemical method and shown to be applicable to prepare some rare earth metal doped intermetallic nanoparticles by directly reducing the oxide precursors.