The current study was conducted to investigate the influence of dietary Arginine levels supplementation on broiler performance, some physiological parameters under summer conditions. One hundred and twenty, one day old unsexed of Arbor Acres broiler chicks, were randomly divided into 4 equal groups in equal 3 replicates of 10 chicks each. The first group was fed control (base diet), the 2^nd ; 3^rd and 4^th  groups fed the control diet supplemented with 0.1%, 0.3%, and 0.5% Arginine, respectively. All chicks were maintained under the same management from 1 to 38 days of age. The ambient temperature during this period fluctuated between (30-35 ^oC). The results were as follows: Compared to chicks given either a control diet or diets supplemented with 0.1 and 0.3% L-Arginine, chicks fed diets containing 0.5% Arginine had significantly the highest final body weight and weight gain values. The two groups received either 0.3 or 0.5 L-Arginine in their diets had recorded the best FCR ratio and the lowest amounts of feed intake at the end of experimental period.  An increase in dietary arginine levels dramatically decreased TL, TC, TG, and LDL during the grower and finisher phases. As the level of Arginine supplementation rose, there was a significant rise in TP, Al, and globin, respectively. No difference in carcass traits was seen among the examined arginine levels. In general, it can be concluded that adding L-Arginine in broilers diet was useful in increasing FCR and lowering FI, blood cholesterol and abdominal fat and dietary added 0.5 L-Arginine/kg diet was more efficient in improving the performance of Arbor Acres broiler chicks under hot climate conditions