The present work reports on the preparation of nickel oxi/hydroxide and gold composite nanoparticulate sols. The precursor was prepared as an alcoholic suspension of nickel oxi/hydroxide. Controlled amounts of 2,4-pentanedione (AcAc) were added to the nickel salt suspension and lead to the formation of a nickel complex. The dependence of the particle size with AcAc titration was followed by Small Angle X-Ray Scattering (SAXS). The results showed that the particle size distribution shifts towards low values with the increase in the AcAc concentration. The complex, obtained by adding an excess of the AcAc ligand, [Ni(AcAc)2]·2H2O, was identified by FTIR spectroscopy and X-ray diffraction. An AcAc specific volume was chosen in order to obtain a homogeneous sol of nickel oxi/hydroxide to which gold was added. The size distribution of the Au particles in this sol was followed by SAXS.