In this work, Fe55Co45 magnetic nanoparticles were synthesized by the chemical polyol method and by the green chemistry method. These magnetic nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, X-ray fluorescence, and vibrating-sample magnetometry. For the green chemistry methodology, we used the phytochemical components present in an aqueous extract of Mangifera Indica leaves. In spite of the fact that polyol method produced more quantity of samples at short times, Fe55Co45 nanoparticles synthesized via the green chemistry methodology had higher saturation magnetization values (92.44 emu/g) with crystallite sizes from 19.1 to 28. 6 nm, suggesting the potential of this benign route to obtain magnetic nanoparticles through an economical an easy way. The resulting nanoparticles may be used for drug delivery carriers and for water purification.