Lattice parameters of specimens deformed plastically at high temperatures are determined between 7 and 293 K. Above and below the well known phase transition temperature of non‐deformed crystals tetragonal and rhombic symmetry is detected after deformation, respectively. The results agree qualitatively with the temperature dependence of lattice parameters calculated for V3Si single crystals under uniaxial pressure. Dislocations created by plastic deformation appear to have the same effect.