Spin coated polymer films of poly(ethylene oxide) (PEG) containing an Er3+ salt, ErF3, were excited by a red (650 nm) dye laser. Strong green and weaker blue luminescence is observed corresponding to emissions from the thermally coupled S-4(3/2) and H-2(11/2) bands and the H-2(9/2) level, respectively. This is the first time upconversion effects of rare earth ions are reported from a polymeric host.