The aquatic species Ceratophyllum demersum and Myriophyllum spicatum were grown in different Cd concentrations (0, 25, 50, 75 mg/l) in a hydroponic system to analyze their detoxification capacity and the suitability of pigments and proline content to serve as biomarkers. Both studied species exhibited the same increasing pattern of Cd removal, when they treated with different Cd concentrations. M. spicatum exhibited a higher accumulation capacity than C. demersum being 1.5, 1.26 and 1.19 fold at the end of the experiment with the cadmium concentration of 25, 50 and 75 mg/l, respectively. Significant differences in pigment and proline contents between the treated and control samples indicated that Cd stress induced oxidative stress response in the studied species. Carotenoides and proline contents showed their partially increasing, especially during the short duration of Cd exposure. Chlorophylls a, -b exhibited the sever effects of Cd concentration on their contents. These responses reflected the suitability of the tested parameters to use them as biomarkers for heavy metal stress