Direct observation of superplastic deformation in shear in a scanning electron microscope in Pb‐62% Sn eutectic alloy at different microstructural levels were performed. The sliding of grains as an entity was observed. Such cooperative grain‐boundary sliding proceeds by means of the sequential shear of grains along shear surfaces, and is accompanied by cooperative grain‐boundary migration. The pattern of shear surfaces at the level of the entire deformed volume is close to one that is predicted by slip‐lines field theory. The processes to accommodate deformation of grain‐boundary sliding include the operation of grain‐boundary migration, intragranular deformation, and grain rotation. A critical analysis of the proposed geometrical models for superplastic flow is given. The model of sequential shear of grains as a result of the movement of cellular dislocations is extended to the case of the two‐phase material, having structure that is typical for superplastic eutectics.