High-strength steels like AISI 4140 are commonly used for high dynamically loaded parts. Increasing demands for lightweight parts with higher performance and efficiency in automotive industry claim improving material properties. An optimised drilling process should enhance the fatigue life of deep-drilled components by the induction of residual stresses in the borehole, without the need for expensive additional processing steps, e.g. autofrettage. Non-destructive testing techniques like magnetic Barkhausen noise analysis offer quick and reliable possibilities to detect and classify material parameters like hardness and residual stresses. The aim of this study is to evaluate and extrapolate the resulting fatigue performance of deep drilled round specimens due to drilling parameters at an early stage of fatigue life. It was shown, that the coercive field strength decreases approximately linear with proceeding fatigue damage. The slope of the degradation coefficient is comparable for different surface layer conditions. This leads to the assumption that the variation of the micromagnetic parameters is caused by fatigue-induced microstructural changes. Therefore, a microstructure-based prediction of the fatigue life by means of micromagnetic measurements can be established.