The Raman spectra of silicon nanoparticles in the size range between d=3.5d=3.5–View the MathML source60nm have been studied experimentally. Scattering processes up to second order are being observed. The experimental results are analyzed in the framework of the phonon confinement model. While this model describes qualitatively the observations for first-order scattering processes, it is not applicable for scattering processes of higher order. From the analysis of second-order scattering, we determine a redshift of the TO phonon at the X and L points.