Molecular dynamics simulations were performed to study the nanoindentation of NiAl and Ni3Al crystals on three surfaces: (100), (110), and (111). The calculated load-displacement curves show discrete drops at certain indentation depths, indicating dislocation bursts during indentation. The hardness values for the two materials were found to depend significantly on the indented crystallographic plane: the (100) surface is the softest for NiAl and the hardest for Ni3Al. We also found distinctive deformation activities in the subsurface region in Ni3Al crystals, while dislocation loops propagate deep into the substrate in NiAl systems.