This study evaluated and compared serum biochemical and haematological parameters of two commercial broiler strains (Arbor Acres and Marshall) during the 28-day starter phase. A total of 180 day-old unsexed chicks (90 per strain) were randomly assigned and reared under uniform deep-litter conditions. Blood samples were collected from 12 birds (6 per strain) on day 28. Results showed no statistically significant differences (p > 0.05) in serum biochemical indices such as triglycerides, cholesterol, lipoproteins, total protein, albumin, and globulin. Similarly, haematological indices and leukocyte differentials were comparable between strains. All measured values fell within established normal ranges for healthy broilers. The findings suggested that under identical management conditions, both strains exhibited similar physiological health during the starter phase. Therefore, strain selection for commercial production may be based on performance traits such as growth rate and carcass yield rather than baseline health metrics.