Variable angle spectroscopic ellipsometry (VASE) measurements were employed to study the optical properties of HgI2. The bulk crystal HgI2 surface was subjected to a 10% KI etching prior to the VASE measurements. SE measurements were performed at room temperature, in air with several different angles of incidence. The uniaxial anisotropic nature of the HgI2 crystal was treated in the VASE analysis. Anisotropic dielectric functions of single crystal HgI2, ε||(wo) and ε⊥(ω), for optical electric field vector oriented parallel and perpendicular to the c axis, respectively, were obtained in the range of ∼2.0 - 5.0 eV. Surface aging effects of the HgI2 crystal, after the 10% KI etching, were characterized by VASE.