Single crystals of Er3+/Yb3+-codoped KY(WO4)(2) with a large dimension up to 30 x 23 x 15 mm(3) and no inclusion have been grown from a mixed flux of K2WO4 and KF by the top seeded solution growth (TSSG) method. The distribution coefficients of Er3+ and Yb3+ in KY(WO4)(2) crystal are 0.94 and 0.8, respectively. Five emission bands are observed at 550-560, 660-680, 850-870 950-1050 and 1450-1600 run regions by 266 run laser pumping. Unlike the cases of the other Er3+/Yb3+-codoped crystals, no upconversion was observed by 976nm laser pumping. (C) 2002 Elsevier Science B.V. All rights reserved.