Electro-deposited pure iron has a quite sharp and isotropic <111>//ND fiber texture and a needle-shaped grain elongated in ND. This pure iron shows an r-value exceeding 7, which is difficult to explain from the texture alone. In this study the deformation behavior of electro-deposited pure iron was investigated to reveal the mechanism behind the extremely high r-value. The post-deformation surface slip lines indicated that the particular <110> plane slips, which are perpendicular to ND, exclusively act in the specimen. The tensile deformation caused by this slip system does not require any decrease in thickness, hence the extraordinary high r-value is mainly attributable to this limitation of the active slip system. Presumably, the needle-shaped microstructure affected the limitation of the slip system.