Objectives: Several factors have been associated with hyperglycemia after kidney transplantation (KTx), including systemic inflammation. This study aimed to investigate the relationship between periodontal status and hyperglycemia in KTx patients. Materials and methods: Forty-four KTx patients were included in this cross-sectional study. Periodontitis severity was categorized into stage I to IV. Fasting blood glucose (FBG) was measured, and hyperglycemia was analyzed at different FBG cutoff points (100 mg/dL, 110 mg/dL, 120 mg/dL, 126 mg/dL, 140 mg/dL). Age, history of smoking, prior type 2 diabetes (T2D), and prior cardiovascular disease (CVD) were considered cofounders. Multivariable logistic regression modelling was performed with periodontitis as the exposure and hyperglycemia as the outcome. Pathway analysis was performed with FBG as a continuous outcome. Results: Periodontitis had increased odds of hyperglycemia from 120 mg/dL FBG cutoff, even after adjustment. In addition, periodontitis severity was positively associated with FBG level (β = 0.323, SE = 0.127, P = 0.011). Conclusion: The findings suggest that periodontitis may be related to increase of hyperglycemia and FBG levels in KTx patients. Clinical relevance: Periodontitis severity and cardiovascular disease were positively associated with FBG levels in KTx patients. Clinicians and patients should be aware of the potential benefit of periodontal care for better glycemic control management.