Lead germanate single crystals (Pb5Ge3O11:PGO) have been grown by the vertical Bridgman method. The dielectric measurements show that the Curie temperature of the PGO crystal is 447 K and the dielectric constant at room temperature is about 30. Thermal properties including specific heat. thermal diffusivity. thermal conductivity and thermal expansion have been investigated as a function of temperature for the first time. The specific heat of the PGO crystals has been measured to be 0.327J/(g K) at 298K. The thermal diffusivity and the thermal conductivity for PGO crystals are about 0.323 mm(2)/s and 0.763W/(m K) at 298 K. respectively, The average thermal expansion coefficients along the a- and c-directions of PGO crystals, calculated from 323 447 K. are 8.68 x 10(-6) and 6.60 x 10(-6), K: however, it changes to 10.55 x 10(-6) and 6.07 x 10(-6) K between 448 573 K. respectively. (c) 2005 Elsevier B.V. All rights reserved.