The present study aimed to investigate the type and degree of water pollution in Lake Temsah. Then, studying the effect of most recorded heavy metals on fish and role of garlic in improving the health status of exposed Red Tilapia. The results during the field survey revealed higher level of lead followed by cupper then iron with no cadmium record. A total number of 165 Red Tilapia fish were equally distributed into five groups each with a triplicate of 11 fish. Lead acetate was added to tank's water of all groups of experiment except the control group. Garlic was added and used as a treatment to selected groups. The groups exposed to Lead acetate only revealed decrease in the RBCs, Hb%, HCT with increase in MCV and MCH and MCHC in the 3^rd and 6^th weeks of the feeding experiment. In addition, leukocytopenia, neutrophilia, lymphopenia with elevation in serum creatinine, ALT, AST in comparison with control group. When garlic added during the feeding experiment, an increase in the survival and significant increase in growth and weight-gain were seen in all treated groups beside significant improvement in the blood parameters and indices. It is concluded that, Garlic at dose 0.25 g/ kg eliminated partially Lead toxicity from the fish body, which in turn improved the growth and immunity.