A new polymorph of lutetium polyphosphate, Lu(PO(3))(3), was found to be isotypic with the trigonal form of Yb(PO(3))(3). Two of the three Lu atoms occupy special positions (Wyckoff positions 3a and 3b, site symmetry ). The atomic arrangement consists of infinite helical polyphosphate chains running along the c axis, with a repeat period of 12 PO(4) tetra-hedra, joined with LuO(6) octa-hedra.