The paper gives a brief overview on the current state of the art of cost-efficiency analysis concerning measures to reduce nutrient immissions into the Baltic Sea. On the basis of a literature review it develops a methodology for a rough estimation of the cost-effeciency of measures intended to reduce nutrient immissions into the Odra river basin and the Odra Estuary. The results are presented as annual marginal costs and absolute costs of the respective measures. Agricultural measures prove to be the most efficient means to reduce nutrient immission – but only up to certain threshold levels and following uneven regional patterns. To realise radical cuts in nutrient immissions, a combined strategy integrating agricultural and waste water treatment oriented measures would be necessary. The project ICZM-Oder was financed by the German Ministry for Education and Research (BMBF 03F0475).