Objectives : To explore the association between HbA1C level and penile implant infection rates and to define a cut-off value that predicted implant infection. Patients and Methods:A multi center prospective study included all patients undergoing penile implant surgery between 2009-15. Preoperative, perioperative and postoperative management were identical for the entire cohort. Univariate analysis was performed to define predictors of implant infection. HbA1c levels were analyzed as a continuous variable and sequential analysis was conducted utilizing 0.5% increments to define a cut-off level predicting implant infection. Multivariable analysis was performed with the following factors entered the model: Diabetes, HbA1C level, patient age, implant type, vascular risk factor number, presence of Peyronie’s disease (PD), BMI and surgeon volume. A ROC curve was generated to define the optimal HbA1C cut-off for infection prediction. Results : 902 implant procedures were performed over this period of time. The mean age was 56.6 years. The mean HbA1c level was 8.0, with 81% of men having a HbA1c >6%. 685 (76%) implants were malleable, and 217 (24%) were inflatable devices. 302 (33.5%) patients had also a diagnosis of PD. Overall infection rate was 8.9% (80/902 subjects). BJU International For Peer Review Patients who had implant infection had significantly higher mean HbA1c levels, 9.5% vs 7.8% (p