Now a days quinolones are frequently used antibiotics at poultry farms but their residual effects by oxidative damage to body of chicken have not been addressed. Therefore, we aimed to investigate the effect of antibiotic residues of ofloxacin on total antioxidants, oxidants, paraoxonase, arylesterase and catalase activities. Five weeks old broiler birds were treated with ofloxacin @ 10 mg/kg b.wt/day for 5 consecutive days through drinking water. Six birds were killed for each time interval for the detection of antibiotic residue in muscles and liver by HPLC with fluorescent detection. Experiment was conducted according to the institutional ethics committee. Health biomarkers including paraoxonase, arylesterase and catalase were analyzed by their respective reference methods and concentrations were measured by photometric method from serum, muscles and liver. Ofloxacin did show a residual effect on day 3 which turned into traces in muscles at the end of study. Oxidant status did increase on day 1 after ofloxacin therapy and level remained high throughout experimental period that may lead to deterioration of broiler meat. Ofloxacin did decrease the muscle arylesterase but did not put significant effect on serum arylesterase. Muscle catalase and serum paraoxonase were significantly decreased by ofloxacin at day 1 of the experiment. However, after 4 days of wash out period for drug, the antioxidants status was improved without any significance. In conclusion our results did show that residues of ofloxacin have deteriorative effects on meat quality by increasing the oxidant level in the muscles and serum.