In‐plane uniaxial magnetic anisotropy is observed in the magnetic hysteresis loops of ultrathin Fe films grown on MgO(001) by means of oblique‐incidence molecular beam epitaxy. The films are deposited from an angle of 45° from the surface normal in the (100) azimuth toward the [100]. The easy axis of magnetization is perpendicular to the incident Fe‐beam direction. A strong structural asymmetry is observed in x‐ray photoelectron diffraction and attributed to an oriented morphology that drives the growth‐induced magnetic anisotropy. ©1995 American Institute of Physics.