The performance of engineering components under conditions of fatigue can be improved by shot peening. The location and magnitude of the highest residual compressive stress, the depth of the compression zone and the stability of the residual stress state during cyclic loading are critical parameters for maximum utilisation of the advantageous influence of shot peening on fatigue performance. For accurate assessment of fatigue lifetime, residual stresses should be considered because they are algebraically summed with applied stresses. Therefore, the development of a non-destructive testing (NDT) method that has the ability to rapidly monitor surface residual stresses has industrial importance when verifying the achievement of the design goals of shot peening. The utilisation potential of the magnetic Barkhausen noise (MBN) technique in shot peening of ferromagnetic steels includes automated sorting of the components and measurement of surface residual stress. This study aims to establish the correlation between MBN emission and the fatigue life of shot-peened AISI 4140 steel.