Magnetic iron oxide nanoparticles exhibit many interesting properties due to their surface chemistry and they can be exploited in biomedical and technological applications. The iron oxide nanoparticles (FeO NPs) using ferric chloride, ferrous chloride, PVP (Poly Vinyl Pyrolidone) and Syzygium aromaticum extract were successfully synthesized by wet-chemical co-precipitation method. The PVP coated FeO NPs and S. aromaticum loaded to PVP coated FeO NPs were systematically characterized by using expository tools. UV-Visible spectroscopy showed the maximum absorbance at 480 nm and 554 nm due to the excitation of surface plasmon vibrations in the FeO NPs formation. Fourier transform infrared (FT-IR) spectrum showed the presence of functional groups of in the form of various band positions and this study confirmed that phenols and primary amines were majorly present. DLS studies revealed narrow size of particles i.e., 399.8 nm and 190.1 nm. Particle size distribution was showed at 256 nm and 153 nm for these samples and zeta potential values were observed at-23.7 and-18.8 mV with greater stability. The X-ray diffraction (XRD) analysis is in good agreement with a high degree of crystallographic nature of particles and the average particle size was found to be 23 nm and 29 nm using Scherrer equation. FT-Raman spectrum showed three main characteristic peaks. The scope of this study was extended by examining the cytotoxicity of PVP coated FeO NPs and S. aromaticum loaded PVP coated FeO NPs on human breast (MCF-7) cancer cell lines. The results suggest that the S. aromaticum loaded FeO NPs acts as a potential anti-cancer agent and are a promising research field for lots of biomedical applications particularly for breast cancer studies.