The aerosolization products obtained from aerosolization by atomization of 22 wt.% nickel nitrate and 23 wt.% ferric nitrate aqueous solutions as aerosolized separately were found to consist of hollow spheres. The characterization of these products revealed that the pyrolysis temperature affects the crystallinity, particle size, particle size distribution, specific surface area, average bulk density and decomposition efficiency of the product. The nickel nitrate aerosolization product was fired at 723, 843, 1013 and 1083 K. The decomposition efficiency at the previously mentioned temperatures was 63, 90, 95 and 96%, respectively. The X-ray results revealed that the aerosolization product of the nickel nitrate at 723 K consists of tiny NiO crystals and other non-crystalline phases, while those obtained at 843 K and higher consist of crystalline NiO. The aerosolization products of ferric nitrate as fired at 933 K and below this temperature were found to be non-crystalline, while those obtained at 1083 K were found to be crystalline. The average particle size was found to increase for all the products by increasing the decomposition temperature of the two nitrate aerosols involved in this investigation. The increase in particle size was attributed to the sintering of the powder particles. On the other hand, the surface area decreases by increasing the decomposition temperature.