The toxicity of copper sulfate was tested as part of the current research (CuSO4.5H2O) as it impacts freshwater snails of three species. Species Melanoides tuberculata, Melanopsis praemorsa, and Viviparus bengalensis are chosen for conducting the current research. Stock solution of copper sulphate was prepared previously and series of concentrations were conducted and were 0, 0.3, 0.5, 0.7, 0.9, and 1 ppm. Then, the mortality of tested species were recorded at each intermittent periods and were 24, 48, 72, 96 hours, respectively of which death has been noticed and recorded. LC50 values were ranged between 0.21 to 0.41, as recommended for application in the farms. To conclude, copper sulphate is highly toxic to laboratory test organisms. More research in this regard should be taken into account in agricultural and environmental work and avoid excessive use of toxic substance as they are common pollutants to freshwaters such as rivers.