The structural properties and magnetic behavior of the Fe50Si50 system were determined using X-ray diffraction (XRD), Mössbauer spectrometry (MS), vibration sample magnetometry (VSM), and scanning electron microscopy (SEM). Samples of Fe50Si50 were melted using an arc furnace, then powder was obtained through a diamond file, and this was passed through different sieves. Finally, nanoparticles of this system were produced by means of surfactant-assisted mechanical alloying. XRD confirmed the presence of the FeSi (CS) and Fe5Si3 structural phases. By transmission MS, it was observed that at room temperature the spectrum is formed by three general components, a doublet associated with the FeSi (CS) phase and two sextets associated with the Fe5Si3 phase; this gives the idea of the distribution of the sizes of particles present in the sample. By VSM, the soft magnetic behavior of the system was ratified and it was determined that the biggest saturation magnetization corresponds to the smallest particles.