A feeding trial was conducted to study the influences of dietary basil leaves powder (BLP) supplements on productive and physiological performance in growing Japanese quail. A total number of 192 unsexed birds (9 days old) were randomly assigned to four equal treatments (48 birds), in six replicates, eight birds each. The 1^st group was used as a control group. The 2^nd, 3^rd and 4^th groups were fed diets containing 0.5%, 1%, and 1.5% BLP, respectively. The findings showed that control diets with BLP levels (especially, 1.5% BLP) had beneficial effects by improving feed conversion ratio (FCR) and decreasing feed intake (FI). Diets containing BLP significantly augmented carcass and depressed abdominal fat weight. Giblets and dressing had no significant effect. Diets with BLP resulted in increasing the absolute weights of the immune organs. The quail fed on a diet with 1.5% BLP achieved significantly the highest values of total protein, globulin, and albumen. A significant lowest value was recorded regarding serum glucose. Lipid profile and thyroid hormones triiodothyronine (T3) and thyroxin (T4) values in BLP-treated groups were significantly better than the control. There was a numerical increase in color, texture, and overall acceptability of quail meat values with the inclusion of all BLP levels compared to the control. Furthermore, net revenue and economic efficiency values were improved for quail-fed BLP diets. In conclusion, BLP can be used as feed additives to boost the productive and physiological performance of growing Japanese quail.