With an increasing prevalence of diabetes, there is a need to risk stratify arthroplasty patients preoperatively and characterize postoperative infections. This study sought to determine if perioperative markers of diabetic control were associated with infection and to further characterize diabetic periprosthetic joint infections (PJI). A retrospective analysis of 506 diabetic patients and 900 nondiabetic patients who underwent primary total hip and knee arthroplasty was performed. In this cohort, an infection rate of 4.7% and 2.0% for diabetic and nondiabetic patients, respectively, was observed. There was no association between infection at 1 year and preoperative hemoglobin A1C or postoperative blood glucose; however, diabetic infections were significantly more likely to be deep (HR = 4.6; p < .001) and present >6 weeks postoperatively (HR = 8.0; p = .001). This study concluded that common markers of glycemic control are not predictive of the increased risk of diabetic PJI and alternative markers should be investigated. (Journal of Surgical Orthopaedic Advances 28(2):127-131, 2019).