Abstract The vanadium redox flow battery (VFB) is one of the most promising stationary electrochemical storage systems. The reduction of system costs is a major challenge in the realization of its widespread application. The high complexity of this technology requires a close linking of technologic and economic aspects in system cost assessment. The present review provides an extensive literature analysis with a focus on techno-economic assessment of VFB. Considered materials, system designs and modelling approaches are assessed and compared in order to present and evaluate the current status of system cost assessment in a transparent way. Systems in a range of 2 kW–50 MW providing energy for up to 150 h are covered in literature resulting in an immense range of specific total system costs of 564–12931 € kW−1 or 89–1738 € (kWh)−1. Based on the data from the reviewed studies, guide values of 650 € (kWh)−1 and 550 € (kWh)−1 for installed VFB systems in a power range of 10–1000 kW providing energy for 4 h and 8 h respectively are derived from literature. Moreover, the relevance of precision in the definition of scope and components for meaningful results of techno-economic assessments of VFB systems is pointed out.