An experiment was conducted to determine the effect of adding formic acid (FA) , sodium diformate (SDF) and probiotics [(Lactobacillus acidophilus (LA)] or Lactic acid bacteria and enzymes (LAE) to a typical corn soybean meal diets on growth performance, some blood parameters, carcass traits, ileum bacterial counts and economic efficiency of broiler chicks. A total number of 150 one-day-old Arbor Acers broiler chicks were classified into 5 equal groups, each was subdivided into 3 replicates with 10 chicks. The control group was fed basal (starter, grower and finisher) diets without supplementation (T1), while the other groups (T2: T5) were fed the basal diets supplemented with 2 g (SDF)/ kg diet (T2); 2 ml (FA)/ kg diet (T3); 1 g (LA)/ kg diet (T4) and 1 g (LAE)/ kg diet (T5), respectively. Feed and water were supplied ad-libitum, throughout the whole experiment which lasted till 35 days of age. The results indicated that: Productive performance of broiler chicks; live body weight, daily weight gain, daily feed intake, feed conversion ratio, protein conversion ratio and energy conversion ratio were not affected significantly by different dietary treatments at whole experimental period, but numerically (T2 and T3) represented the best feed conversion ratio being (1.56 and 1.57), respectively, without significant differences among treatments compared with that fed control diet (1.62). Plasma total protein, albumin and uric acid were significantly different compared to control group. Carcass traits indicated that different dietary treatments (T2: T5) had no effects on carcass characteristics compared with control group. Feed additives used, in the current study tended to increase values of total bacterial count and lactic acid bacteria, but the values of coliform and salmonella counts were decreased in comparison with the control group. Economical evaluation showed that, relative economic efficiency, was improved when broiler chicks fed 2 g (SDF)/ kg diet (T2) or 2 ml (FA)/ kg diet (T3) and the values were 5.49 and 4.77% more, respectively when compared with that fed control diet. It could be concluded that, supplementation of basal diets with FA or SDF enhanced productive economic efficiency of broiler chickens, without affecting carcass traits.