Copper sulfate is used as a fungicide in poultry feed and for the medication of drinking water.This Study was carried out on weekly basis. At the end of each week feed consumption, weight gain, morphology and histopathology of liver, kidney, heart and gastrocnemius muscle were noted. Chicks showed various clinical symptoms including loose fecal material, poor feather growth, entheritus and coccidosis disease. Hemorrhages were seen on liver, kidney, heart and gastrocnemius muscle. Fat deposition on liver,heart and muscle was observed. Infilteration of mononuclear cells and fibrosis was seen in liver, kidney and gastrocnemius muscle. The purpose of present work was to know the lowest toxic dose level. This work may be a guideline for poultry breeders including vaccination schedule to avoid clinical signs and mortality in broiler chicks.