Monodisperse, crystalline silver nanoparticles are synthesized by sonolytically assisted decomposition of silver oxalate and oleate precursors in dibenzylether. Oleic acid and oleylamine are used as capping agents. The diameters of the obtained particles vary from 6 to 10 nm depending on the sonification time and the precursor material. The particles are stable in non-polar media. A 2D and 3D assembly of the as-prepared nanoparticles is observed. Particle sizes and dispersities are characterized by transmission electron microscopy and image analysis. The decomposition characteristics of the different precursor compounds are investigated using UV–Vis spectroscopy and thermogravimetry.