Abstract: The crystal and magnetic structures of intermetallic compound PrFe 10.5 V 1.5 and its nitride PrFe 10.5 V 1.5 N x are studied by powder neutron diffraction. Data analysis by means of Rietveld's profile refinement suggest that in the ThMn 12 type tetragonal structure, V atoms occupy 8i site and N atoms enter the interstitial 2b site. A brief discussion of the effect of nitrogenation on the magnetic properties is given.