In this study, starch nanoparticles were synthesized via a green nanoprecipitation method, utilizing water as the sole solvent and ethanol as the antisolvent. A two-factor factorial experimental design was employed to determine the starch solution concentration and the volume ratio of the starch solution to ethanol for achieving the smallest particle diameter and the highest yield. Under the conditions of a 1% (w/v) starch solution concentration and a starch solution-to-ethanol volume ratio of 1:5, the smallest nanoparticles were produced with a maximum yield of 82±3%. The mean diameter of these nanoparticles determined by Dynamic Light Scattering (DLS) was 49±14 nm. Field Emission Scanning Electron Microscopy (FE-SEM) revealed a spherical morphology, while Fourier Transform Infrared Spectroscopy (FTIR) confirmed the nanoparticles has the same molecular structure as the native starch. The contact angle of 36.31° was obtained for these the nanoparticles. Their performance in stabilizing Pickering emulsions was evaluated using emulsion index. The emulsion index of 0.85 was determined after 24 hours, which it gradually decreased to 0.70 after 7 days and then it remained constant for 2 months.