The objective of this research was to investigate the effects of impregnation materials on the thermal conductivity of six-layered laminated veneer lumber (LVL) made of beech and Scots pine. Zinc chloride and ammonium sulfate as impregnation chemicals and urea formaldehyde (UF) and phenol formaldehyde (PF) adhesives as bonding agent were used to produce LVLs. The veneers were impregnated by using the vacuum-pressure method. The thermal conductivity test was performed based on ASTM C 1113-99 hot-wire method. Results showed that the impregnation chemicals increase the thermal conductivity of LVLs. As impregnation chemicals, the highest value was obtained with ammonium sulfate. In addition, the thermal conductivity of LVL made of beech was higher than that of LVL made of Scots pine. The thermal conductivity of LVL bonded with FF was absolutely higher than LVL bonded with UF in both wood species.