There is considerable interest in mitigating secondary electron emission (SEE) from surfaces and electrodes due to their deleterious effects. Since surface conditions are known to affect SEE, here the role played by a vacancy and an interstitial which are simple examples of surface defects, is probed through Monte Carlo simulations. The effect of the lattice imperfection on the frequency-dependent permittivity are obtained on the basis of density functional theory. The calculation results are in rough agreement with previous experimental reports. Of the three cases, the SEE characteristic with a single vacancy is predicted to have the highest values, while those for a perfect lattice are the lowest. The results underscore the benefit of annealing or reducing surface roughness and inhomogeneities through laser or charged-beam surface treatments.