BACKGROUND: Various antioxidant has been studied clinically for reducing CIN. OBJECTIVES: To assess the efficacy of antioxidant supplements in the prevention of CIN (CIN). METHODS: MEDLINE, EMBASE, Cochrane Library, Clinical-Trials.gov, and Scopus databases through November 2016. Randomized, controlled trials of various antioxidant supplements that used for the treatment of CIN with enough data for meta-analysis. The risk of bias and overall strength of evidence of studies were assessed. Two reviewers independently extracted data and assessed study quality. All statistical analyses were performed using RevMan v.5.3. RESULTS: A total of 13 studies (including 8 randomized, controlled trials) met the selection criteria for evaluating the protective efficacy of antioxidant against CIN. There was a significantly improvement in kidney function among the antioxidant recipients, compared with control subjects (mean difference in calculated creatinine clearance, 2.95 mL/min; 95% confidence interval [CI], 1.15–4.77mL/min), as well as a reduced risk of acute renal failure (risk difference, 0.5%; 95% CI, 0.15–0.98). The strength of evidence was generally insufficient for comparisons of the need for renal replacement, and mortality. The significant variability in findings on antioxidant efficacy against CIN may reflect a lack of uniformity in the study methodologies and the limited number of clinical trials. LIMITATION: Too few studies were done in patients receiving antioxidant treatment for CIN. Thus, a number of randomized clinical trials are needed on antioxidant efficacy against CIN. CONCLUSIONS:: The findings of the reviewed studies show promise in preventing CIN with the use of antioxidant. Nonetheless, based on the currently available evidence, no recommendations for clinical practice can be made at this time.