This experiment was conducted to evaluate the effect of selenium (Sel-Plex) and chromium picolinate on some blood parameter of local laying hens reared under high environmental temperatures. Two hundred and seventy laying hens (24 week-old) were divided into nine groups, 30 hens per group using two levels of selenium (0.3 and 0.5 mg/kg diet) and two levels of chromium picolinate (1200 and 1400 μg/kg diet). The control group was fed a basal diet. The obtained results can be summarized as follows: Laying hens fed the Se and Cr-supplemented diets achieved significantly higher   total counts of blood erythrocytes and leukocytes, and lymphocytes, hemoglobin, packed cell volume as compared to their control counterparts. However, there were significant decreases (P≤0.05) in total monocytes but total heterophil were not affected compared with the un-supplemented control group. Dietary supplementation with Se and Cr caused significant  (P≤0.05) increases in blood plasma levels of total protein, globulin, chloride, calcium, phosphorus, triiodothyronine, and thyroxine, while levels of albumin, albumin: globulin ratio, creatinine and urea were decreased as compared to those of the control group. Hens fed the Se and Cr-supplemented diets attained significantly lower (P≤0.05) levels of plasma concentrations of cholesterol, glucose, total lipids and  triglycerides as well as activity of transaminases (ALT and AST) as compared to their control counterparts. From the present results, it is concluded that enhancing hen's diets with selenium (as Sel- Plex) and chromium picolinate singly or in combination at levels of 0.3 mg Se plus 1400 μg Cr /kg diet can consider as an effective management practice for reducing the adverse effects of heat stress for laying hens.