In the present investigation, Cu_0.5Ni_0.5 nanoparticles were synthesized using high energy ball milling of a mixture of Cu₂O, NiO, and graphite powders. The mixture of powders was milled up to 50 h. The 30 h milled sample was heat treated at various temperatures for 1 h in a vacuum tube furnace. The effects of milling time and heat treatment temperature on the powder particle characteristics were studied employing X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), and vibrating sample magnetometer (VSM) techniques. XRD results indicated incomplete formation of Cu_0.5Ni_0.5 after 30 h of milling. Further heat treatment at 500 ^∘C led to the formation of a single phase Cu_0.5Ni_0.5 powder. FESEM and TEM images of the heat treated sample showed spherical Cu_0.5Ni_0.5 nanoparticles with a mean particle size of 15 nm. Magnetic properties data measured by VSM of the above sample are correlated well with the XRD results. Coercivity and saturation magnetization have been approximately achieved at 25 Oe and 18 emu/g, respectively.