Complete determination of all Raman active lines in the range between 180 and 480 cm(-1) for an orthorhombic beta-FeSi2 lattice has been performed by accurate polarized Raman measurements on beta-FeSi2 and a crystal rotation method along the <111> axis. The 20 Raman active lines including 7 new lines in the range between 180 and 480 cm(-1) were observed. Further polarization relations for each observed Raman lines were analyzed from their intensity changes as a function of crystal rotation angle. The components of the Raman tensor of li-FeSi2 were discerned from the polarization curves. (C) 2004 Elsevier B.V. All rights reserved.