The master thesis consists of conceptual design, analysis and final design of a road bridge over the Sotla river in municipality Bistrica ob Sotli. The bridge forms regional connection between town of Bistrica ob Sotli and Kumrovec and it also serves as a border bridge between country of Slovenia and Croatia. For the basis and help at the design process, the Conceptual design of replacement bridge over Sotla river (Potočan 2017) was used. In this conceptual design, the possible solutions of crossing the river were studied. We examined the existing project documentation; we evaluated it and selected the most suitable bridge type. Within this process we have taken into account numerous parameters such as geometric road design, topography od terrain, geological composition of the soil and last but not least, regulation of Sotla river. The best design option was post-tensioned concrete bridge with only one span and length of 36,7 m. The abutments on each side of the bridge are descending under inclination corresponding to riverbank and they reach solid bedrock at the river bottom. We defined appropriate materials of which the load-bearing structure is made of and we analysed all the possible actions acting on the bridge in its lifetime. We made suitable calculation model based on bridge geometry and we carried out static analysis of the load-bearing structure. We discussed ultimate limit state (permanent and seismic actions) as well as serviceability limit state and we calculated corresponding element forces. We determined the required number of prestressing cables; we calculated necessary prestressing force and evaluated all instant and time dependent losses of prestress. After calculating all inner forces of abutment and superstructure, the required quantity of reinforcement in the critical cross sections of the structure were determined. We also checked that the stresses of the concrete and cables are within allowed limits according to serviceability limit states.