Abstract: Research is ongoing to develop screening and testing programmes for endocrine disrupting effects of new chemicals and in the focus of this development are the fish test species common carp (Cyprinus carpio). In this study we have developed quantitative enzyme linked immunosorbent assays (ELISA) for VTS in common carp. The working range of the ELISA was 11.25 to 2,000 ng mL-1 (75-25% specific binding/maximum antibody binding [B/B0]) with a 50% B/B0 intra- and interassay variation of 3.9% (n = 10) and 12.5% (n = 30), respectively. This ELISA is capable of detecting VTG as low as 6 ng mL-1 and can accurately detect VTG in even 10 μL of plasma. The ELISA was applied to measurement of VTG production by male carp (Cyprinous carpio, Cyprinidae) fish exposure to ethynylestradiol. The results showed that the amount of VTG produced in plasma of exposed fish increased in logaritmic order comparing to the control group and the ELISA described here could be used as an indicator of water pollution to estrogenic pollutants.