Unlike the design of other types of buildings, the approach to the design of underground buildings is very specific because it is constantly subject to changes and adjustments to the real situation. Design is most often approached through an empirical approach, numerical modeling and the method of observation, or the so-called integral method of design. In this paper, the railway tunnel "Brajdica" was used as an example of implementation for the design of excavation and stabilization of the tunnel by the integral design method. The first part of the paper describes tunnels, their classification and the modern way of construction, but also some of the traditional methods. Excavation stabilization techniques with all associated elements of the support system are also described. Further in the paper an example of mentioned implementation for the design of the excavation and stabilization of the railway tunnel "Brajdica" is given. Empirical approach was used to obtain rock mass parameters and to determine support systems based on RMR and Q classification. Furthermore, numerical analysis is provided to obtain the actual stress - strain parameters of rock mass along the tunnel route. A program of geotechnical monitoring and measurement is envisaged, which not only checks the stability and applied design calculation model, but also checks the basic concept of the massif's reaction to the performance of underground excavation and the effectiveness of support systems and all measures to stabilize excavation.