Direct observation of ferroelastic switching in thick single crystals of the superconductor YBaCuO is reported. The coercive stress required for the movement of domain walls is not large. This points to the possibility of an easy removal of twinning in this material, with an attendant increase in the critical current density. The domain walls observed, indexed, and moved by applying unaxial stress are: {110}, (100) and (010). In addition, creation and movement of walls which could be either {113} or {103} or {013} is also observed. On heating the crystals to the tetragonal phase, only the {110} walls are found to disappear, as expected.