<p>The size effect and mechanical property anisotropy of commercial pure nickel foils with various thickness/grain size ratio (<i>t/d</i> = <i>λ</i>) ranging from 1.4 to 5.0 were studied by uniaxial tensile testing along rolling direction (RD), transverse direction and 45° direction. Both the strength and ductility decrease with increasing grain size or decreasing <i>λ</i>. The proposed constitutive equation derived based on size effect exhibited a good coincidence with experimental results. Taylor factor distribution and deformation microstructure for pure nickel foils undergoing uniaxial tensile deformation was strongly sensitive to the texture. The &lt; 111 &gt; // RD fiber plays a very important role on the mechanical property of pure nickel foils. Usually, the microbands parallel with slip planes are developed in grains with &lt; 111 &gt; orientation. With the increase of the volume fraction of &lt; 111 &gt; // RD fiber, the strength increases and the ductility decreases. The in-plane anisotropy factor was influenced by the annealing temperature and <i>λ</i>. Compared with strength, the loading orientation has a larger effect on the ductility.</p>