A total number of 120, 1d old unsexed chicks were randomly distributed and divided equally into 4 dietary treatment groups with 3 replicates each. All broiler chickens were kept under similar managerial conditions. Basal starter and finisher diets were supplemented with two types of organic acids as follows: T1: basal diet (control, without supplementation), T2: basal diet + 2% citric acid (CA), T3: basal diet + 1% acetic acid (AC) and T4: basal diet + 1% citric acid + 0.5% acetic acid. Two corn-soybean based basal diets were formulated to be fed during starter (1 to 21 d, 22.13% CP and 3088 Kcal ME/ kg diet) and finisher (22 to 42 d, 19.82% CP and 3154 Kcal ME/ kg diet) periods.  Growth performance parameters, feed conversion ratio, some carcass characteristics and some lymphoid organs were estimated. Some blood parameters (total protein, albumin, total cholesterol, creatinine, ALT and AST) and histomorphological samples and parameters were determined at 42 day. Also, European productive and economic efficiency were calculated. Results indicated that; chicks fed diets supplemented with a mixture of citric acid (1%) and acetic acid (0.5%) had significantly (P ≤ 0.05) the highest values of body weight, body weight gain and the best feed conversion ratio, while recorded the lowest feed intake compared to the other treatments. Moreover, using mixture of supplementation significantly (P ≤ 0.05) improved performance index (PI) in comparison with the control treatment. A significant (P ≤ 0.05) beneficial effect of citric acid and acetic acid or their mixture as feed supplementation were found concerning dressing, giblets and some immune organs percentages at 42d of age compared to the control group. Mixture of citric acid and acetic acid supplementation significantly (P ≤ 0.05) increased some serum biochemical constituents (total protein, albumin, globulin and liver enzyme; ALT), while, total lipids and cholesterol concentrations were significantly (P ≤ 0.05) decreased. Histomorphological sections of the small intestine revealed villi height and villi widths were significantly (P ≤ 0.05) increased with the supplementation of organic acid alone or in their mixture compared to the control group.  Also, the mixture of 1% CA + 0.5% AC supplementation had beneficial effects on economical efficiency. In conclusion, there are some beneficial effects of using a mixture of citric acid and acetic acid (1% citric acid + 0.5% acetic acid) in the diets of chicks on productive performance, carcass traits, with no harm effect on health under experimental conditions.