THE WATER quality characteristics and some heavy metals cations (Fe2+, Mn2+, Zn2+, Cu2+ and Pb2+) of Damietta estuary and in front of Mediterranean coastal shoreline were evaluated through four successive cruises (February 2008 to November 2008). Twelve sites were selected from the two sectors. The results obtained showed that serious deterioration of quality of water at Damietta estuary compared with Mediterranean shoreline. The concentrations of major cations and anions increased progressively while moving away from Damietta Estuary to the sea which reflect the effect of seawater intrusion into estuary. Contrarily, nutrient salts values in the estuary showed elevated values due to heavily polluted waste water poured into estuary where the nutrient salts content of the Mediterranean Sea water depend on its levels in Damietta Estuary. The distribution order of heavy metals concentrations in water samples was Fe > Mn > Pb > Zn > Cu > Cd.