In the current work narrowly distributed and stable Ru nanoparticles (NPs) with mean diameters within 1.7 to 2.8 nm interval were prepared by reduction of RuCl3 with ethylene glycol (EG) as a solvent and a reducing agent as well as polyvinylpyrrolidone (PVP) as a stabiliser in the temperature range from 170°C to 198°C. Besides a typical polyol technique, Ru NPs synthesis using microwaves as well as sodium borohydride reduction at room temperature was applied as an effective alternative approach. The effect of heating conditions, Ru/PVP ratio, reducing agent and metal precursor concentrations on the particle size was studied. Microstructure of Ru NPs was characterised by UV Vis, XPS and HRTEM. Higher PVP/Ru ratios and reduction temperature gave slightly smaller nanoparticles with narrower size distributions, while no clear effect was observed when the initial ruthenium concentration was varied.