A saccharide-assisted hydrothermal route starting from a single iron precursor was employed to study the influence of the reducing saccharides on the formation of iron oxide (Fe3O4) nanoparticles. Iron oxide nanoparticles (NPs), which were confirmed by X-ray diffraction analysis, were successfully synthesized by a hydrothermal method in which mannose, maltose, lactose and galactose served as reducing agents. The formation of Fe3O4 nanoparticles was also approved by Fourier transform infrared spectroscopy (FT-IR). Samples exhibit different crystallite sizes estimated based on line profile fitting as 12±2, 9±2, 13±3, and 9±3 nm for mannose, maltose, lactose and galactose, respectively. Magnetic characterization results reveal superparamagnetic features of the nanoparticles obtained with galactose, mannose and maltose.