Abstract: The present study was carried out to determine the effect of dietary organic acid mixture supplementation on performance (body weight changes, feed intake, feed efficiency, egg production) egg quality and concentration of some blood serum parameters in laying hens. A total 53 week old 44000 white Lohmann LSL laying hens which were allotted into 4 groups, each containing 11000 hens. The hens were fed with diets (17% CP% and 2795 Kcal Kg-1 ME). Supplemented with 0% (control group No. 1), 260 ppm (group, 2), 520 ppm (group 3) and 780 ppm (group, 4) of organic acid mixture (formic acid and salt of butyric, propionic and lactic acids). The dietary organic acids significantly modify live body weight in groups 2 and 3 and non significantly improved in group 4 when compared with control one. Organic acids supplementation at 780 ppm (group 4) significantly increased egg production by about 5.77% compared with the untreated group, while the lower levels (groups 2 and 3) showed non significant effect. On the other hand dietary organic acid had no effect on the average egg weight, while showed a higher percentage of small, medium and X-large egg size and reduction in large egg size compared with control group. The results revealed that no effect of organic acid on feed intake but improvement egg mass and feed efficiencies was observed. Higher inclusion level of organic acids (780 ppm) improved egg shell quality and non significantly increased egg shell calcium and protein content, improved yolk index, while slightly reduce albumen index. The data revealed that linear increase of serum calcium and concentration of total serum protein. From the obtained data can be concluding that organic acid supplementation at level 780 ppm of laying hens diet improve live body weight, improve persistence of lay and from economical point of view we can concluded that organic acid addition (780 ppm) amazing increase the economical efficiency of layer production.