The current study was conducted to investigate the effect of Silymarin extract on productive performance and the immune-physiological status of growing (Cairina Moschata Domestica) ducklings. A total number of 200 - day old ducklings were obtained from a commercial hatchery. Upon arrival they were brooded at 33⁰C for one week and then individually weighed and divided randomly into four treatments of 50 birds in five replicates 10 ducklings each. The first group was served as a control and fed the basal diet without any supplementation, while the second, third and fourth groups were fed the basal diet supplemented with silymarin extract at levels of 0.6, 0.9 or 1.4 g/ kg dietlevels, respectively. The duration of the experiment was 70 days. Results showed that silymarin at 0.6 g/kg diet level positively affected feed conversion ratio, live body weight and body weight gain compared with the control one. Moreover, silymarin recorded highly significant values of globulin fractions (α, β, and γ-globulin), immunoglobulins and thyroid hormone concentration. Additionally, silymarin had significantly improved liver functions markers (ALT, AST and ALP) and serum lipid profile and significantly decreased lipid fractions (cholesterol, low density lipoprotein and triglycerides). In a similar way, silymarin induced significant improvement in the antioxidant status including low malondialdehyde (MDA) concentration and higher total antioxidant capacity, glutathione peroxidase and superoxide dismutase enzymes activity. Additionally, pathogenic bacterial counts were significantly reducedgrowth compared with control group. Conclusion: silymarin extract at 0.6 g/kg diet, may be useful for improving growth performance, antioxidant status, liver functions. Notable linear decrease in the serum lipid profile concentration and pathogenic bacteria were observed in treated growing ducks.