This chapter studies how immigrants impact on Italian economy. The issue is addressed following the channel output decomposition approach by means of which the effect of immigration is measured with respect to per capita value added and its components. The investigation is carried out at sector level during the 2008–2011 time period. The results show that the main channel through which migration impacts on value added varies on sectoral basis. While at aggregate level, in Manufacturing and in Other Services the impact goes mainly through capital intensity, in the Construction and in the Commerce sectors the principal channel is via total factor productivity.