Oil jet peening is a surface modification process developed for the introduction of compressive residual stresses. In this process, a high-pressure oil jet impinges on the surface to be peened. Specimens made of AISI 1040 steel were peened at oil pressure of 50 MPa. Residual stresses induced on the oil jet peened specimen was in the order of -200 MPa. Standoff distance influenced the residual stress induced and also the erosion and surface roughness. Fully reversed cantilever bending tests conducted on the peened and unpeened conditions revealed the improved performance of the oil jet peened specimens.