SUMMARY The increased use of heavy metals like lead, copper, mercury and cadmium in industry and agriculture, and thier subsequent intrusion in indeterminate amounts into the environment has caused ecological and biological changes. In our study 50 water samples were collected from Abu-Tig, Assiut Manquabad, Bany-Qurra and Dairut, at winter and summer 1992/1993. Water samples were subjected to analysis for the presence of lead, copper, mercury and cadmium. Our results revealed that lead concentrations in water of the different examined areas were 1.940, 0.810, 0.810, 0.3!4 and 0.790 ppm in winter and 0.220, 0.270, 0.313, 0.222 and 0.200 ppm in summer at Abu-Tig, Assiut, Manqabad, Bany-Qurra and Dairut respectively. Abu-Tig and Assiut areas registered the highest concentration in winter and Manqabad and Assiut in summer. The examined water samples were above the permissible limit of WHO (0.10 ppm) or United States Environmental Protection Agency (US EPA) which is 0.05 ppm. The highest concentration of copper in water samples collected from Manqabad and Bany-Qurra were 0.42 and 0.088 ppm in winter and 0.522 and 0.39 p < strong>pm in summer. The examined water samples showed values less than the permissible limits adopted by US EAP (1.0 ppm). A concentration of 18.700 and 12.400 ppb were the highest concentrations of mercury in water samples collected from Assiut and Bany-Qurra in winter and 24.800 and 15.600 ppb in Bany-Qurra and Dairut in summer. The examined water samples showed values more than the permissible limits adopted by US EPA (2 ppb). The highest concentration of cadmium in water at Bany-Qurra and Manqabad (0.009 and 0.007 ppm) in winter and Dairut and Manqabad (0.012 and 0.015 ppm) in summer. Water samples showed cadmium values less than the permissible limit (0.01 ppm) excep < strong>t water samples collected from Manqabad and Dairut in summer which reached to 0.015 and 0.012 ppm respectively.