Rice husk is considered a main agricultural waste in Iraq. High purity SiO2 NPs were produced from rice husk by enhanced precipitation and developed leaching processes for the preparation of silica from RH. In this study, pre-treatment for rice husk was with 3N HCl, and calcination at 700°C was achieved, then followed with a leaching process with (1.5, 2, 2.5, 3) N NaOH concentrations. The characterizations of the prepared SiO2 NPs were studied by X-ray fluorescence (XRF), X-ray diffraction (XRD), and atomic force microscopy (AFM). The results show that the prepared SiO2 NPs have an amorphous structure with a high purity of 99.75%. The results of the X-Ray confirm the amorphous nature of the extracted SiO2 NPs. Also, the AFM results indicated that the average diameter of the SiO2 NPs was 85 nm. It was noted that the leaching processes and pretreatment methods determine the structure, particle size, and quality of the synthesized SiO2 NPs.