The effects of surface damage on the secondary electron emission characteristics of a natural diamond (100) surface have been investigated using ultraviolet photoelectron spectroscopy and scanning electron microscopy. Surface damage was intentionally induced by abrading the (100) diamond face with diamond paste. Removal of the damage was achieved by a sequence of ion implantation, graphitization, electrochemical etching and oxygen/argon plasma etching. Prior to characterization performed between steps in the sequence, the surface was hydrogenated by exposure to a hydrogen plasma in attempts to create a negative electron affinity surface condition. Upon removal of the surface damage, the secondary electron yield from the negative electron affinity surface was enhanced by a factor of ˜20 over that from the damaged negative electron affinity surface.