Magnetic transmission soft X-ray microscopy has been used to study element-specifically the magnetization reversal behavior of (Co84Cr16)(87)Pt-13 alloy thin films with a lateral resolution of 35 nm. Our results indicate that the magnetization switching is carried out by a random nucleation process that can be attributed to the reversal of individual grains. We found evidence of a large distribution of the switching fields at the nanogranular length scale, which has to be considered seriously for applications of CoCrPt systems as magnetic high-density storage materials. (C) 2004 Elsevier B.V. All rights reserved.