This paper covers concepts and calculations related to truss girders. The theoretical background related to girders, girder divisions, and static determination of truss girders are briefly stated. The concepts of axial load and buckling, dimensioning with respect to buckling and axial load are also theoretically treated. The main goal of the paper is to analyze the strength of the truss structure. Two different truss types, Pratt and Warren, were selected for analysis. Prior to the truss analysis itself, the input data and dimensions were defined. The loads were calculated, and the dimensions of the transverse and longitudinal beam profiles of the bridge were checked according to them, with regard to the cross-sections and the material. During the analysis of the trusses, the static determination was checked for both versions of trusses, and the axial forces in the truss rods were calculated. It is defined which rods are under pressure and which are under tensile load. Dimension check for axially loaded rods was performed, as well as control of buckling stability criteria of the relevant pressure-loaded rods. The results of the calculation are proof that the selected types of trusses, profiles and material from which they are made of meet the criteria of strength, as well as the criteria of stability to buckling.