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Forged components are known to show high cyclic and monotonic mechanical properties. This is mainly due to a better compactness and a finer microstructure introduced by the forming process. However, this good mechanical behaviour is sometimes a source of anisotropy especially when the microstructural heterogeneities are not randomly distributed and/or oriented. This study aims at describing the high cycle fatigue response of a forged bainitic steel. This material contains a lot of elongated manganese sulphide (MnS) inclusions, oriented as a function of the rolling or forging direction. Specimens with different orientations relative to the rolling direction are tested in fatigue under push–pull uniaxial and torsion loads. The influence of “inclusion clusters” is clearly demonstrated via the observation of the failure surfaces. Experiments show that the anisotropic fatigue behaviour is due to a change in the crack …