A method for non-destructive characterization of plastic deformation in bulk materials is presented. The method is based on X-ray absorption contrast micro-tomography using X-rays from a synchrotron radiation source. The method can be applied to materials that contain marker particles, which have an atomic number significantly different from that of the matrix material. The size of the marker particles can be 1-2 mum and their positions (x, y, z) are determined as a function of strain. The use of the method is demonstrated by a compression study of an aluminium specimen containing tungsten marker particles. (C) 2004 Elsevier B.V. All rights reserved.