Strain induced by He‐ion bombardment in 3–4‐μm‐ thick surface layers of V3Si single crystals was studied using the x‐ray back‐reflection divergent‐beam method. The strain matrix of the surface layer was determined. Analysis of the x‐ray line broadening as a function of increasing dose showed that the strain varied with the depth distance from the surface. The depth strain gradient was confirmed by x‐ray measurements carried out at different depth levels and by the application of a dual‐element x‐ray target. Calculations showed that the observed line broadening induced by a low dose of bombardment was closely related to the nuclear stopping power in the samples. For a high dose this simple relationship apparently did not hold. An annealing study showed that the strained surface layer relaxed in a two‐step process. Strain reduction was time‐independent (from 15 min to 2h) up to 600 °C. At 700 °C strain relaxation continued discontinuously, indicating that another mechanism became active at this temperature. An attempt was made to relate the present data to previous work on the degradation of superconducting properties of A‐15 structures due to radiation damage.