The paper describes hydrochemical conditions and trophic status of lakes Mętno and Ostrów, the largest water bodies in the Cedyński Landscape Park. The study was conducted in 1998-2000. The lakes were found to differ in their water mass dynamics: Lake Mętno was polymictic, water dynamics of Lake Ostrów placed it near bradymictic. The oxygen regime of near-surface and near-bottom layers, nutrient contents and Secchi disc visibility are indicative of considerable fertility of the lakes studied. The Mętno should be classified as strongly eutrophic. Spatial and tempral changes of mineral forms of nitrogen were typical of eutrophic reservoirs showing a clear trend towards deposition of nitrogen in bottom sediment. The eutrophic nature of the lakes studies is confirmed also by the high concentrations of phosphorus compounds. All the mineralisations indices evidenced an averege mineralisation level, typical of the Western Pomeranian surface waters. The scheme of anion dominations was following: HCO₃^- + CO₃^2- > SO₄^2- > Cl^-.

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