Nickel oxide nanostructures were synthesized via a sol-gel combustion method using glucose, glycine and tartaric acid fuels. The effect of the fuel type on the formed nanostructures was studied. The as-prepared products were characterized by means of FE-SEM, HR-TEM, XRD, and FT-IR analyses. The results exhibited that the used fuels gave NiO products with different morphologies, and the glucose fuel produced pure NiO nanoparticles with the smallest crystallite size (ca. 8.2 nm). The adsorption properties of the NiO products for the removal of malachite green dye (MG) was examined. Using a batch method, various parameters affecting the adsorption properties were studied. The results revealed that NiO nanostructure generated from the glucose fuel had the highest adsorption capacity