Fatigue is one of the main causes of damage in steel structures. It may occur when a structure is subjected to repeated cyclic loadings. The fatigue shows itself in the form of creation and developing of cracks. A crane runway-girder is a typical example of a structure subjected to this kind of stress. Basic knowledge about fatigue, about calculation of fatigue loadings and stresses, about process of fatigue assessment and about typical structural details are presented in the attached work. The fatigue assessment of the defined crane runway-girder according to STN EN 1993-1-9 is applied in the practical part of the attached work.