Objective: The aim of the study was to investigate the changes of the oxidant and antioxidant system in blood samples before and after nasal packing following nasal septoplasty. Material and Methods: A total of 23 patients, 7 females and 16 males, who were planned to undergo nasal septoplasty were included in the study. Nasal packing was removed at postoperative 48 hours in all patients. Blood gases, serum advanced oxidation protein products (AOPP), serum and erythrocyte malondialdehyde (MDA) levels, and catalase (CAT) activity were measured at preoperative 24 hours (period 1), postoperative 24 hours (period 2) and on postoperative day 15 (period 3) in all subjects. Results: pO2, pCO2, 02 saturation and HCO3 values were similar at all three periods. MDA level was lower and CAT activity in erythrocyte was higher at period 3 compared to periods 1 and 2. Serum CAT activity was also increased at period 3 compared to period 1. Serum MDA and AOPP levels did not change among the periods. Conclusion: The findings suggest that a decrease in oxidative stress as indicated. by the decrease in lipid peroxidation and increased CAT activity may have a protective role via free radical-scavenging properties 15 days after the operation.