Polarized far infrared (FIR) reffectance technique was applied to study the optical properties of a bulk wurtzite zinc oxide (ZnO) single crystal. Room temperature polarized FIR reffectance spectra were taken at various angles of incidence, from 20 to 70. The theoretical polarized FIR reffectance spectra were simulated based on the anisotropic dielectric function model. Good agreement was achieved between the experimental and the theoretical FIR reffectance spectra. Through this work, a complete set of reststrahlen parameters of a bulk wurtzite ZnO at the Brillouin zone centre was obtained. Additionally, other FIR optical properties such as the real and the imaginary parts of the complex dielectric function, real and imaginary parts of the refractive index, the absorption coeficient and the reciprocal of the absorption coeficient were also obtained by using numerical calculation. Polarized far infrared (FIR) reffectance technique was applied to study the optical properties of a bulk wurtzite zinc oxide (ZnO) single crystal. Room temperature polarized FIR reffective spectra were taken at various angles of incidence, from 20 to 70. The so- reffectance spectra were simulated based on the anisotropic dielectric function model. Good agreement was achieved between the experimental and the theoretical FIR reffectivity spectra. , other FIR optical properties such as the real and the imaginary parts of the complex dielectric function, real and imaginary parts of the refractive index, the absorption coeficient and the reciprocal of the absorption coeficient were also obtained using numerical calculation.