Objective: Both pregnancy itself as well as obesity contribute to oxidative stress status. Our aim in this study was to investigate the correlation between obesity and oxidative stress in pregnant women by measuring maternal total antioxidant status (TAS). Material and Methods: One hundred-three pregnant women between 37-40th gestational weeks (GW) were enrolled in the study. In all cases, age, gravida, parity, height, and weight values were recorded and TAS values were measured in peripheral blood samples. The subjects were divided into two groups as non-obese (<30 kg/m(2)) and obese (>= 30 kg/m(2)) according to their body mass index (BMI). The linear correlation between BMI and TAS levels were investigated using Spearman correlation test, also TAS values of two groups were compared. The comparison between the groups were done using Mann Whitney test. Results: Sixty-nine cases were non-obese and 34 cases were obese. Age and parity were higher in obese group (p<0.05), while gravidity, GW at delivery and birth weight were similar between the groups (p>0.05). No linear correlation between BMI and TAS values was found in the pregnancies after 370 GW (p>0.05). Although the TAS values were higher in obese cases than non-obese cases [1.705 (0.11) vs 1.690 (0.22)] this difference was not statistically significant (p>0.05). Conclusion: It has been noted that the BMI had no impact on the oxidative stress in pregnant women who are at term. This circumstance should be considered in studies about oxidative stress in pregnancies.