Nanosized copper aluminate (CuAl2O4) spinel particles have been prepared by a precursor approach with the aid of ultrasound radiation. Mono-phasic copper aluminate with a crystallite diameter of 17 nm along the (3 1 1) plane was formed when the products were synthesized using Cu(NO3)2·6H2O and Al(NO3)3·9H2O as starting materials, with urea as a precipitation agent at a concentration of 9 M. The reaction was carried out under ultrasound irradiation at 80 °C for 4 h and a calcination temperature of 900 °C for 6 h. The synthesized copper aluminate particles and the effect of different processing conditions such as the copper source, precipitation agents, sonochemical reaction time, calcination temperature and time were analyzed and characterized by the techniques of powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and Fourier transformation infrared spectroscopy (FT–IR).