A total of 120 random samples of dairy water supply, raw cow's milk from different, dairy farms, dairy shops and street vendors (30 samples each) Assiut, Egypt during the period from April 2018 to march 2019 to estimate concentration of Lead, cadmium, manganese and Mercury inwater supply of dairy farm and dairy farms, dairy shops and street vendors raw milk samples in Assiut governorate, Egypt. Statistical analytical results of heavy metals mean values (ppm) in dairy farm water supply were 0.192± 0.006, 0.0005± 0.0001, 0.950± 0.0034 and 0.648± 0.002 respectively. While in in dairy farm cow's milk they were 0.084± 0.026, 0.032± 0.067, 0.830± 0.002 and 3.523± 0.002 (ppm) respectively. But in in dairy shop cow's milk were with means 0.217± 0.045, 0.053± 0.067, 0.900± 0.002 and 4.200± 0.038, respectively. The street vendors cow's milk the mean values were found to be 0.289± 0.067, 0.064± 0.045, 0.954± 0.056 and 4.769± 0.052 respectively. All results of heavy metals were in concentration higher than Maximum permissible limits. The health importance of heavy metals and methods of control are discussed.