Intermetallic Ni3Al has been deposited by means of magnetron sputtering on substrates with an amorphous surface structure. The source was a homogeneous mixture of Ni-AI 75:25 % in the solid phase. The lateral and perpendicular grain sizes are below 20 nm. The morphology of the layer was studied by transmission electron microscopy. The hardness of a single Ni3Al layer and of a multilayered Ni3Al/Ni are measured by nanoindentation and compared with the hardness of a bulk coarse-grained polycrystalline Ni3Al.