The intent of the study was to investigate the effect of dietary inclusion of sodium bicarbonate (NaHCO3) on blood profile of caged layers during summer. One hundred sixty commercial layers were divided into 20 experimental units/replicates (8 layers/replicate), which were further allotted to five treatment groups (4 replicate/treatment). Five iso-nitrogenous (CP 17%) and iso-caloric (ME 2700 Kcal/Kg) diets (A, B, C, D and E) were prepared with or without addition of NaHCO3. Diet A, was without NaHCO3 and served as control whereas, diets B, C, D and E contained 0.5, 1.0, 1.5 and 2.0% NaHCO3, respectively. These diets were fed to the experimental birds from 26 th -37 th weeks of age (12 weeks). At the end of the experiment, blood samples of two birds from each replicate were collected for the analysis of blood profile. Results of the study revealed that serum glucose, white blood cells count, serum urea, plasma chlorides, serum cortisol and serum glutamic-oxaloacetic transaminase concentrations were found to be significantly (P<0.05) higher in control group, whereas, blood hemoglobin concentration, red blood cells count, plasma sodium, potassium, bicarbonate, serum total protein and serum albumen concentrations were significantly (P<0.05) higher in the birds fed diet containing 1% NaHCO3. Whilst, Serum uric acid concentration was significantly (P<0.05) higher in those fed 2% NaHCO3.However, packed cell volume, erythrocyte sedimentation rate, serum creatinine, alkaline phosphatase, plasma calcium,plasma phosphorus, serum globulin and serum glutamic pyruvate transaminase concentrations were not affected due to the dietary treatments. Serum cholesterol, triglycerides and low density lipoprotein concentration were significantly (P<0.05) decreased, whereas, serum high density lipoprotein concentration was found to be significantly (P<0.05) increased by dietary inclusion of NaHCO3. Birds fed diet containing 1% NaHCO3 showed significantly (P<0.05) higher concentration of estrogen, progesterone, T3 and T4 hormones. It was concluded that being economical and easy to handle, dietary inclusion of NaHCO3 may be a better choice to reduce or at least ameliorate the harmful effects of heat stress on blood chemistry in caged layers reared in summer conditions.