The advantages and disadvantages of the three techniques used to examine dislocations in ice, viz., etch pitting-replication, transmission electron microscopy, and X-ray topography (XT), are reviewed, and it is shown that XT is the most useful of these techniques. The introduction of high-intensity synchrotron radiation for XT demonstrated that conventional XT observations are of dislocation structures which have undergone recovery. Some of the important dynamic observations and measurements of dislocations which have been made using synchrotron X-ray topography are outlined.