Abstract Background Blood loss occurs significantly more frequently during total hip and knee arthroplasty than among any other type of orthopedic operation, which can sometimes lead to requiring a blood transfusion. Although allogeneic blood transfusion has been identified as a risk factor for postoperative surgical-site infection following arthroplasty, results are inconclusive. The purpose of this study was to conduct a systematic meta-analysis to investigate whether having an allogeneic blood transfusion significantly increases the risk for surgical-site infection, particularly after total hip and knee arthroplasty. Methods We performed a systematic review and meta-analysis using random-effect models. Using an electronic database search, we selected 6 studies that included data on 21,770 patients and among these studies compared the postoperative infection rate between an allogeneic blood-transfusion exposure group and a nonexposure group. We calculated the pooled odds ratios and 95% confidence intervals for the groups. Results The prevalences of surgical-site infections in our pooled analyses were 2.88% and 1.74% for the transfusion and nontransfusion groups, respectively. The allogeneic blood transfusion group had a significantly higher frequency of surgical-site infections based on pooled analysis using a random-effect model (pooled odds ratio = 1.71, 95% confidence interval: 1.23-2.40, P  = .002). Conclusion Allogeneic blood transfusion is a significant risk factor for increasing the surgical-site infection rate after total hip and knee arthroplasty.