This study was designed to evaluate the effects of administering coriander seed extract to Japanese quails at various concentrations on weight gain, liver enzymes such as ALT and AST, and male sex hormones. Forty male quails randomly divided into four groups. The groups were distributed as follows: control group received regular feed and water without any addition, the second group received a 10% concentration of the seed extract with drinking water, the third group received a 20% concentration of the seed extract with drinking water, and the fourth group received a 40% concentration of the seed extract with drinking water. The experimental period extended for four weeks duration. The results showed a significant increase in weight in the 10%, 20%, and 40% treated groups compared to the control one. ALT levels significantly decreased in the 10% and 20% treated groups compared to the control group, while the 40% coriander seed extract-treated group showed a significant increase in ALT and AST levels compared to the other treated groups. The levels of SSH, ICSH, and testosterone hormones didn't show a significant difference in the 10% extract-treated group, while their levels decreased significantly at the 20% and 40% doses compared to the control group and the 10% supplemented group. The study concluded that a 10% concentration of coriander seed extract was the best in terms of inducing weight gain while maintaining liver health and sex hormone levels, whereas higher concentrations had negative effects on liver function and sex hormone levels.