Electron back-scattered diffraction (EBSD) in scanning electron microscopy (SEM) is already extensively used for creating orientationbased 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 (≈0.1 •) is better than the accuracy of EBSD systems.