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 management 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/ 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. European productive and economic efficiency were calculated, also. Results indicated that; chicks fed diets supplemented with a mixture of citric acid (1%) and acetic acid (0.5%,T4) 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 citric acid and acetic acid supplementation significantly (P ≤ 0.05) improved performance index (PI) in comparison with the control treatment. A highly significant (P ≤ 0.05) beneficial effects of citric acid and acetic acid or their mixture as feed supplementation on dressing, giblets and some immune organs percentages at 42 days of age compared to the control group. Citric acid with 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 that villi height, width and 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, based on the obtained experimental results reported herein and from the nutritional and economical point of view, 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 characterized by the best productive performance, carcass traits, some serum biochemical constituents, intestinal histological parameters and better economic efficiency without any adverse effects on health under experimental conditions.