We present the results of ab initio Hartree-Fock calculations of the LaMnO ₃ (001) and (110) polar surfaces. Using 7- and 8-plane slabs periodic in 2D along the x, y-axes, we compare the properties of a stoichiometric slabs with structural oxygen vacancies, and non-stoichiometric, defect-free slabs, analyze the dispersion of the effective charges near the surface, and calculate the surface energy, for both ferromagnetic and antiferromagnetic spin orderings in a slab.