The nuclear magnetic resonance ofFe57has been observed in iron specimens in the form of powders ofvarious sizes, foils, and whiskers. Our results are consistent with previously reported work of Gossard,Portis, and Sandle on enriched iron, and with the work of Robert and Winter on natural iron. We find thatthe resonant frequency varies slightly among nominally pure iron specimens taken from different sources,suggesting that it is somewhat sensitive to impurity content. Prestrain of the specimen has a marked effect,the resonance in cold-rolled foil being very broad and weak compared to that observed in annealed foils.Observations of nuclear magnetic resonance in iron whiskers oriented both axially and transversely in therf coil offer interesting confimation of the domain wall enhancement mechanism put forth by Gossard andPortis. The temperature dependence of theFe57resonance has been investigated in the range 77°–785°K.