Magnetite nanoparticles (Fe3O4) were prepared by chemical coprecipitation method using ferric chloride (FeCl3) and heptahydrate ferrous sulfate (FeSO4·7H2O) salts employing sodium hydroxide (NaOH) as a precipitant. To determine the size, shape, and chemical makeup of the produced magnetite nanoparticles, the generated powders were examined by transmission electron microscope, scanning electron microscope, atomic force microscope, and X-ray diffractometer. It was found that the magnetite powder had made a face-centered cubic crystal structure and spherical-like particle form with particle diameters of about 30 nm. The magnetic properties of magnetite nanoparticles were evaluated using a vibrating sample magnetometer. The obtained superparamagnetic properties of the produced nanoparticles, with saturation magnetization and coercivity of 50.75 emu/g and 30.09 Oe, respectively, allow them for applications in drug delivery, MRI contrast agent, catalysis, degradation of antibiotics, antibacterial activity, removal of heavy metals and organic dyes, etc. [ABSTRACT FROM AUTHOR]