This study aimed to determine the prevalence of diabetic kidney disease (DKD) and evaluate the association between Hemoglobin Glycation Index (HGI) and incident DKD among newly diagnosed patients with type 2 diabetes mellitus. This retrospective cohort study used electronic medical records of newly diagnosed type 2 diabetes mellitus patients between 2018–2019 with 5 years of follow-up. HGI was calculated from the relationship between HbA1c and fasting plasma glucose (FPG) at baseline and categorized into tertiles. Logistic regression was used to analyze the association. Results: A total of 115 patients were included. Thirty-five patients developed DKD, yielding a 5-year cumulative prevalence of 30.43%. Compared with those without DKD, patients who developed DKD had a significantly higher baseline FPG (173.37±67.41 vs. 136.23±36.34 mg/dL, p<0.01), higher HbA1c (8.21±1.66 vs. 7.47±1.48%, p<0.01), and higher triglyceride levels (178.85±105.69 vs. 134.2±59.31 mg/dL, p<0.01). When categorized by HGI tertiles, no significant association was observed between HGI levels and incident DKD either before or after adjustment for confounders