The development of the global construction market was accomplished not only by the frequent improvement of the characteristics of structural materials, but also by discovering new ways of quickly project realisation. Innovations in terms of mechanization, logistics, design process, and the production process of structural elements are some of the key factors in contribution to the reduction of the entire construction process. One of the fields in which the improvement of the production process has been achieved is certainly the field of steel structures, or more precisely, the field of thin-walled elements formed by the process of cold-forming. At its very beginning, the orientation was set to finding the optimal cross-section shapes. Later, additional improvements were made in order to exploit more efficiently the possibilities that the process of cold forming offers. One of the many improvements was introduction of the web holes. This production method not only influenced on the decrease of the structural weight, but also provided the possibility of more efficient use of the space in buildings. Consequently, electrical, plumbing or heating installations can be placed within the thickness of walls and floor slabs. The research of this doctoral dissertation is oriented on thin-walled cold-formed elements with web holes, subjected to the simultaneous load of compression and bending. An extensive experimental investigation was carried out in three phases: (i) determination of the mechanical properties of the material, (ii) measuring of the initial geometric imperfections and (iii) eccentric axial load testing of the cold-formed steel elements. The experimental research was numerically simulated with the use of the Abaqus software. These simulations served as a groundwork for model calibration for subsequent parametric analyses, which were carried out aiming to determine the influence and sensitivity of various factors on the behaviour and bearing capacity of cold-formed elements with web holes. Element length, cross-section shape, the number and size of the web holes, as well as the axial load and bending moment intensity were parameterized. It was observed that for elements, for which the loss of stability was governed by the local or distortional buckling shape, the linear function of the interaction diagram yields results that are not always on the safety side. Moreover, it was noticed that the interaction curves of the elements with the web holes „move“ towards the inner side of the diagram, i.e. towards the boundaries of the criteria established in SRPS EN 1993-1-3. Hence, a new set of equations was proposed for the purpose of controling the axial compressive load-to-bending moment interaction of cold-formed steel elements.