THE COMBUSTION synthesis technique using glycine and ……..urea as fuels and nickel nitrate as an oxidizer is able to produce nano crystallite nickel oxide powder. The effects of fuel type, fuel-to- oxidizer ratios (F/O) and temperatures on phase composition and crystallite size of the combustion products were investigated. Thermogravimetric analyses (TGA) were performed to analyze the thermal behaviors of the starting materials. The products were analyzed using X-ray diffraction (XRD), Particle Size Analyzer (PSI), Transmission electron microscope (TEM) and surface area measurements. Optimization processes showed that the best F/O was 1:1 for glycine and 4:1 for urea. The best temperature was 400 °C to obtain crystallite size in nano scale, i.e. 13.4 nm for powder produced using urea with high surface area 83.8 m2/g and 23.7 nm using glycine with surface area 40.6 m2/g. On the other hand, the combustion process in absence of fuel is not efficient in preparing nano nickel oxide. Comparison with previous studies shows that our preparation method is efficient than the commonly used method.