Effect of wollastonite nanofibers on the improvement of thermal conductivity coefficient of Medium-Density Fiberboard (MDF) was studied here to find a possible solution to decrease hot-press time as a bottle-neck during composite production. Nanowollastonite was applied at 10%, based on the dry weight of wood fibers. Density of the control MDF boards was g/cm3. Thermal conductivity coefficient was measured using an apparatus based on Fourier’s Law for heat conduction.