OBJECTIVE Trigger finger (TF) is a hand disorder causing the fingers to painfully lock in flexion. Diabetes is a known risk factor; however, whether strict glycemic control effectively lowers risk of TF is unknown. Our aim was to examine whether high HbA(1c) was associated with increased risk of TF among individuals with diabetes. RESEARCH DESIGN AND METHODS The Swedish National Diabetes Register (NDR) was cross-linked with the health care register of the Region of Skane in southern Sweden. In total, 9,682 individuals with type 1 diabetes (T1D) and 85,755 individuals with type 2 diabetes (T2D) aged >= 18 years were included from 2004 to 2019. Associations between HbA(1c) and TF were calculated with sex-stratified, multivariate logistic regression models with 95% CIs, with adjustment for age, duration of diabetes, BMI, and systolic blood pressure. RESULTS In total, 486 women and 271 men with T1D and 1,143 women and 1,009 men with T2D were diagnosed with TF. Increased levels of HbA(1c) were associated with TF among individuals with T1D (women OR 1.26 [95% CI 1.1-1.4], P = 0.001, and men 1.4 [1.2-1.7], P < 0.001) and T2D (women 1.14 [95% CI 1.2-1.2], P < 0.001, and men 1.12 [95% CI 1.0-1.2], P = 0.003). CONCLUSIONS Hyperglycemia increases the risk of developing TF among individuals with T1D and T2D. Optimal treatment of diabetes seems to be of importance for prevention of diabetic hand complications such as TF.