Ni/Cu(1 0 0) films are known to exhibit an "inverse" reorientation transition at 8-10 ML. In contrast to Fe or Co ultrathin films one observes that the magnetization rotates from in-plane to out-of-plane upon increasing the thickness. The driving force for this phenomenon is the tetragonal distortion of the film which results in a volume uniaxial anisotropy, which favors an out-of-plane orientation of the magnetization. The effect of submonolayer coverage of Fe and Mn on Ni reorientation transition is studied by means of Magneto-Optic Kerr effect (MOKE). Fe overlayers are found to have a marked influence on the interface anisotropy of Ni films resulting in a strong reduction of the critical thickness. In the submonolayer regime, interface anisotropy favors out-of-plane magnetization. Extrapolation to the fully formed interface shows a negative anisotropy. Mn overlayers did not have any dramatic effect on the SRT thickness. Hence do not change significantly the surface anisotropy. © 2004 Elsevier B.V. All rights reserved.