Homogeneous nickel nanoparticles were synthesized and supported over m-ZrO₂ through a simple ultrasonic process. The microscopic and magnetic characterization of nanoparticles showed high quality and effective monodisperse size distribution. The catalytic performance of the samples, containing only 1% wt nickel, was evaluated for CO₂ methanation reaction. The experimental results showed high activity (70%) and excellent selectivity to CH₄ (90% at 720 K). This low-cost and simple fabrication method of a nanocatalyst proves to be a potential candidate for further application.