This paper investigates the costs of wastewater treatment (including sludge management) within the Danube catchment countries A, CZ, SK, HU, SL, RO, BG and UA. TK is considered as well. Additionally, the paper compares the total costs of wastewater management (including sewerage) with the incomes in the different countries. The annual costs of wastewater treatment in Austria are about 30 €/p.e. y for large plants with nitrogen and phosphorus removal. In low income countries of the Danube and Black Sea catchment areas they are at a maximum 30% lower than in Austria. However, the incomes in countries like Bulgaria, Romania or Ukraine are 85% to 90% lower. The total annual costs for wastewater management (sewer development plus treatment) amount at least to 90€/p.e. y. Considering the level of income in those countries, financing of wastewater management completely by charges of the population equivalents connected is not feasible. Therefore other approaches for financing wastewater treatment are required.