Press hardening of Boron steels, mainly the 22MnB5 grade, has been implemented during more than a decade in several structural components of the automotive sector, mostly in the body-in-white (BiW). The process combines sheet forming and heat treatment in one single die quenching step, to produce components with complex geometry and strength up to 1600 MPa. In press hardened steels, fatigue behaviour is very sensitive to surface defects or irregularities, either intrinsic or introduced during forming operations such as trimming. This work addresses the understanding and prediction of fatigue resistance of press hardened steels from a Linear Elastic Fracture Mechanics (LEFM) approach. The size of fatigue originating defects has been evaluated and used to estimate the fatigue limit for different surface conditions (coated and uncoated), different coatings (Al-Si and Zn) and different edge conditions (polished and mechanically trimmed).