In an effort to elucidate the role of defects on the anodic behavior of copper single crystals, information has been gathered about the etch pits formed at dislocations on the (111) face. Anodic etching has been carried out in chloride, chloride/bromide, bromide, and chloride/iodide solutions, with and without copper salt added, as well as in , , and . In halide solutions dislocation pits have been found to be formed over a large range of current densities and solution compositions, whereas no preferential nucleation at dislocation intersections has been detected in other solutions. The role of small misorientations of the surface from (111), as well as the etching of (100) and (110) surfaces has also been investigated. The influence of such parameters as current density, solution compositions, and orientation of the copper surface on the formation and characteristics of such pits is discussed.