Aim. This study was aimed at evaluating prooxidant-antioxidant balance (PAB) in patients with systemic lupus erythematosus (SLE) and its relationship with laboratory findings and clinical manifestations. Methods. In this case-control study, 60 patients with SLE and 60 healthy individuals were enrolled. The blood samples were collected and their sera were separated. Subsequently, the prooxidant-antioxidant balance value was evaluated using PAB assay for each sample. Results. The mean of PAB values in SLE patients was significantly higher than healthy controls (147.3 ± 42 versus 84.8 ± 32.2 HK, P < 0.0001). Furthermore, in SLE patients, there was a positive significant correlation between the PAB and erythrocyte sedimentation rate (ESR) (r = 0.492, P < 0.001). In addition, the PAB values in patients with alopecia, discoid rash, oral ulcers, arthritis, and nephritis were significantly higher than those without these manifestations. Conclusion. The findings of current study showed that the mean of PAB was significantly higher in SLE patients and PAB was correlated with ESR. Moreover increased PAB was found in SLE patients with alopecia, discoid rash, oral ulcers, arthritis, and nephritis. These findings suggest that the measurement of PAB may be useful to show oxidative stress condition in SLE patients.