Abstract. Ni nanoparticles embedded in an amorphous SiO2 matrix were produced by a modified solgel method. This method resulted in nanocomposites with a controlled size distribution and good dispersion of the metallic particles. The particle-size distributions were found to have an average radius of 3nm, as inferred from transmission electron microscopy, X-ray-diffraction analysis, and magnetic measurements. Magnetic characterizations revealed that samples exhibit superparamagnetic behavior above the blocking temperature TB, 20KTB40K, and absence of a shift along the field axis on hysteresis loops measured at TTB, indicating that the metallic nanoparticles are also free from an oxide layer.