The phase transition and microwave dielectric properties of LiY(W1-xTex)(2)O-8 ceramics (0.0 <= x <= 0.2) were investigated in this paper. X-ray diffraction (XRD) results show that there is phase transition from wolframite to scheelite structure due to Te6+ substitution for W6+. The phase of LiY(W1-x,Te-x)(2)O-8 changed from wolframite to scheelite structure completely for the x >= 0.1 compositions after sintering at 875 C degrees/2 h. The dielectric constant and Q x f value decrease with the increase of x when x >= 0.05. The temperature coefficient of resonant frequency (tau(f)) changed from positive values into negative values with the increase in x value. Among the compositions examined, those with x = 0.2 sintered at 850 degrees C/2 h had the best dielectric properties, including epsilon(r) = 14.3. Q x f = 4042 GHz, and tau(f) = -6.05 ppm degrees C-1. (C) 2010 Elsevier B.V. All rights reserved.