It has been found that dislocations in LiNbO3and LiTaO3single crystals can be decorated by electric‐field‐enhanced diffusion of platinum or gold into the crystals at temperatures in the order of 600°C with voltages in the range of 250 to 1000 V/cm. To demonstrate the use of the technique, examples of low‐angle boundary networks in LiNbO3and LiTaO3are shown. The general characteristics of the as‐grown dislocation network in a [101¯0]‐growth‐axis LiNbO3crystal are described, and the effect of annealing on the dislocation array in LiTaO3crystals is discussed.