The effect of EDTA " Ethylendiaminetetraacetic acid' in reducing the soluble heavy metals (Fe, Mn, Zn, Cu and Pb)contents in sewage waste water and muscles of Nile tilapla (Orecchromis niloticus) was studied in an investigation for 90 days period. The work was carded out at Central Laboratory For Aquaculture Research (CLAR) Abbassa, Abu-Hammed, Sharkia Governorate). A total of 315 Nile tilapia fingerlings (20±2g weight) were divided randomly into 21 aquaria, 15 fish for each representing 7 treatment groups in triplicates. Results showed that, all fish in treatment containing the highest EDTA levels 0.750 g/1 died af­ter 3 days of the experimental start. The heavy metal contents sewage wastewater, and in fish muscles declined with each increase in EDTA concentration. The chelating agent of EDTA increased with decreasing of heavy metals in water.