The present study was undertaken to evaluate the efficacy of aspirin as anti-heat stressor. Broiler chicks were reared on a standard diet up to 14 days of age. Thereafter, the chicks were randomly distributed into three dietary treatment groups viz., T1 (Control group: Standard diet), T2 (Standard diet with aspirin@250 mg/kg) and T3 (Standard diet with aspirin@500 mg/kg). Each treatment was having five replicates of eight birds per replicate. Experiment was carried out during hot-dry (April-May, 30.0±0.7 0 to 37.0±1.4 0 C, Rh, %: 58.05±1.32 to 70.11±0.82) summer. Feed intake and live weight gain was comparable among the treatments but FCR, protein and energy efficiency improved significantly (P<0.001) on aspirin supplementation. The relative yield of thymus and bursa at 4 th and 6 th week of age improved significantly (P<0.05). The percentage of protein, aspartate transaminase (AST) and alanine transaminase (ALT) increased significantly (P<0.001) due to aspirin supplementation at 4 th as well as 6 th week of age. While H:L ratio, serum corticosteron and serum cholesterol (only at 42 nd day of age) decreased significantly (P<0.001) in aspirin supplemented groups at 28 th as well as 42 nd day of age. Supplementation of aspirin at 500 mg/kg reduced relative expression of HSP70 in jejunum tissues during 28 th or 42 nd day of age. It can be concluded that aspirin supplementation 500 mg/kg in diet of heat stressed broilers improved performance as well as welfare.