Convergent-beam electron diffraction near a dislocation in silicon shows that some of the higher-order Laue zone lines and Kikuchi lines are split. The splitting of crystal-lographically equivalent reflections is different. These can be explained in terms of the theory of diffraction contrast of imperfect crystals. The splitting and unsplitting of the reflections correspond to the visibility and in visibility of the dislocation. Convergent-beam electron diffraction provides a powerful means for the study of crystal defects with high spatial resolution.