Electron back-scattered diffraction (EBSD) in scanning electron microscopy (SEM) is already extensively used for creating orientation-based microstructure images of polycrystalline materials. In an analogous way, Kikuchi patterns have been recently applied for creating polycrystalline orientation maps using a transmission electron microscope. Main components of the new system are similar to those of the SEM-based systems. The first steps are pattern acquisition and correction of the images. They are subsequently followed by automatic indexing of the patterns. Finally, from orientations obtained in a grid of points, a map is created. The system using transmission electron microscopy (TEM) has a good spatial resolution of about 10 nm. Its accuracy in orientation determination (approximate to0.1degrees) is better than the accuracy of EBSD systems. (C) 2003 Elsevier Science B.V. All rights reserved.