We have measured the off-specular polarized neutron reflectivity of a periodic array of rectangular polycrystalline magnetic Co dots, which were prepared by a combination of electron beam lithography and molecular beam deposition. The dots have strong shape anisotropy, imposed by a length-to-width ratio of 4:1. The intensity of the first-order off-specular satellite reflection was monitored as function of the magnetic field parallel to the rows of dots, allowing us to analyze the magnetization reversal process using the four spin-polarized scattering cross sections. (C) 2003 American Vacuum Society.