Luminescent properties of Sm3+-co-doped (La,Eu)(2)W3O12 under near-UV light excitation have been investigated. La0.5Eu1.5W3O12 shows efficient red emission at 616 nm and is about 1.7 times higher than Y2O2S:Eu3+ in photoluminescence (PL) peak intensity under 395 nm light excitation. Meanwhile, 0.1 mol Sm3+-co-doped La0.5Eu1.5W3O12 is over 5 times higher than Y2O2S:Eu3+ in PL peak intensity under 405 nm light excitation. These results imply that Sm3+-co-doped (La,Eu)(2)W3O12 is a candidate of red phosphors for near-UV light-emitting diodes (LEDs), though the Sm3+ co-doping causes an increase in thermal quenching of PL. (c) 2007 The Electrochemical Society.