Single crystal of Yb, Tm:KLu(WO4)(2) (Yb, Tm:KLuW) with the size of 47 x 32 x 15 mm(3) has been grown by the top-seeded solution growth (TSSG) method. The absorption spectrum was measured at room temperature. The measured specific heat is lower than that of KGd(WO4)(2) (0.502 J/gK) at 100 degrees C, but it is similar to that of Yb:KLuW (0.365 J/gK) at 90 degrees C. The measured mean linear coefficients of thermal expansion are alpha(c) = 16.61 X 10(-6) K-1, alpha(c*) = 15.04 x 10(-6) K-1, alpha(a) = 11.91 x 10(-6) K-1, alpha(a*) = 11.50 x 10(-6) K-1, alpha(b) = 5.91 x 10(-6) K-1. The thermal conductivity coefficients are 2.71, 2.60, 2.22, 3.32 and 3.14 W/mK at 30 degrees C along the a, a*, b, c* and c directions, respectively. The results indicate that the crystal has a large anisotropy. The large anisotropy indicated that we should heat or cool the crystal with the temperature changing at a lower speed. (c) 2006 Elsevier B.V. All rights reserved.