This study was aimed to investigate how the consumption of high fructose corn syrup (HFCS) affects blood parameters of broilers. Total 120 chickens were divided into three groups including 4 subgroups in each with free access to food and water for 42 days. The control group received no additional treatment, while the second and third groups were fed diets containing 5% or 10% HFCS, respectively. On the last day, broilers were euthanized, and 5 mL blood samples were collected for hematological analyses. Results indicated no significant differences in red blood cell (RBC) or hemoglobin (HGB) levels between the control and 5% or 10% HFCS- treated groups. However, 10% HFCS treatment significantly increased packed cell volume (PCV) and mean corpuscular volume (MCV), while 5%-HFCS increased mean corpuscular hemoglobin (MCH) and decreased mean corpuscular hemoglobin concentration (MCHC) compared to the control group. Total leukocyte counts (TLC) and monocyte values remained unaffected by HFCS treatments. Notably, 5% HFCS treatment increased basophil, heterophil, and
heterophil/lymphocyte ratio while decreasing lymphocyte. Conversely, 10% HFCS treatment reduced eosinophil and heterophil, increasing lymphocyte counts. In conclusion, our study suggests that dietary fructose intake can modify certain hematological parameters, potentially serving as early indicators of future systemic or metabolic issues.