Nanoparticles may provide advanced biomedical research tools based on polymeric or inorganic formulations or a combination of both. They have the potential to be used in many different biological and medical applications as in diagnostic tests assays for early detection of diseases, to serve as tools for noninvasive imaging and drug development, and to be used as targeted drug delivery systems to minimize secondary systemic negative effects [1]. The influence of poly(N-vinylpyrrolidone) (PVP) with different molar mass on the synthesis of magnetite (Fe3O4) nanoparticles was studied in the present work. The resultant material was studied by the X-ray diffraction method using a DRON-UM diffractometer (-2 method, =1.93604 Å). (Fig. 1). Furthermore, by using the Scherrer’s equation, the crystalline grain diameters of the Fe3O4 particles was found to be about (14  1) nm. FT-IR absorption spectra of PVP coated Fe3O4 nanoparticles and pure PVP were measured with a PerkinElmer Spectrum 100. FT-IR Spectrometer in the spectral range of 650–4000 cm–1. A comparison of the spectra of the prepared Fe3O4/PVP nanoparticles and pure PVP reveals similar absorption bands in regions of 3600–2400 cm−1 and 1650–650 cm−1. The absorbent peak centered at 1289 cm–1 is due to C–N stretching vibration of PVP. The peak observed in pure PVP at at 1660 cm–1 belongs to C=O group. No shift was observed in the sample Fe3O4/PVP. It indicated that large excessive PVP remained on this sample, probably just remained free on the surface, despite the successive washing steps were done after the synthesis. The excessive free PVP molecules prevent the aggregation of the magnetic particles.In summary, the present work reports on the properties of magnetite (Fe3O4) nanoparticles synthetized with poly(N-vinylpyrrolidone) (PVP) with different molar mass. The characterization and functionalization of Fe3O4 nanoparticles with PVP opens the possibility of formulating a new generation of magnetic materials.