This paper reports nanoindentation studies of the effect of Ta and N content on the mechanical properties of magnetically soft high moment FeN and FeTaN thin films prepared by dc magnetron sputtering. The FeTaN films were deposited on oxidized silicon (100) substrates with a series of FeTa targets in which the Ta content varies from 0 to 25wt%. The hardness (H) and Young's modulus (E) were measured by the Nano Indenter at nine indenter penetration depths: 20, 30, 40, 50, 60, 80, 100, 120 and 200 nm. The inherent hardness values of these films (no substrate effect) can be determined at penetration depths ranging from 20 to 60 nm for the 500 nm thick film used in the study. It was found that for the films deposited from the pure Fe target when the nitrogen flow rate increases from 0 to about 0.5 sccm the hardness of the film increases. However, a decreasing trend in hardness of these films was observed on further increasing the nitrogen flow rate. On the other hand, for the films prepared from the targets with the Ta content in the range of 5–15wt%, the hardness increases whenever Ta and N contents increase. These effects are clearly illustrated by 3-D and contour hardness and Young's modulus maps in this paper.