Background: Poor health literacy (HL) has received much attention recently as a risk factor for poor health outcomes especially among patients with chronic diseases. The degree to which HL affects health outcomes is unknown among patients with type 2 diabetes mellitus (T2DM) in Kuwait. This study aimed to investigate the association between HL and glycated hemoglobin (HbA1c) among patients with T2DM. Methods: 356 patients with T2DM were selected from 27 primary care clinics covering the state of Kuwait. HL was measured by the Short Test of Functional Health Literacy in Adults (STOFHLA). Prevalence of uncontrolled HbA1c was estimated and its association with HL was modeled and tested using Poisson regression with log-link function and robust variance-covariance matrix, while adjusting for several confounders. Results: The prevalence of uncontrolled HbA1c was 77.8%. Among those with inadequate or marginal HL, about 50.7% have uncontrolled HbA1c. The prevalence of uncontrolled HbA1c among those on diet alone was 36.3% lower compared to those on mixed treatment regimen (APR = 0.637, 95% CI: 0.455-0.891, PV = 0.008). The prevalence of uncontrolled HbA1c among patients on oral hypoglycemic (OH) drugs alone was 22.3% lower compared to those on mixed treatment (OH plus Insulin) regimen (APR = 0.777, 95% CI: 0.697-0.865, PV < 0.001). For every one-year increase in age, there is 1.4% reduction in the prevalence of uncontrolled HbA1c (APR = 0.986, 95% CI: 0.978-0.994, PV < 0.001). For one STOFHLA score increase, there is 0.3% reduction in the prevalence of uncontrolled HbA1c (APR = 0.997, 95% CI: 0.994-1.00, PV = 0.055). Finally, for every year increase since T2DM onset, there is 1.1% increase in the prevalence of uncontrolled HbA1c (APR = 1.011, 95% CI: 1.003-1.019, PV = 0.008). Conclusions: The prevalence of uncontrolled HbA1c among patients with T2DM in Kuwait is high. Half of T2DM with inadequate or marginal HL have uncontrolled HbA1c. Patients on diet alone or OH alone have lower prevalence of uncontrolled HbA1c compared to those on mixed treatment regimen. Older T2DM patients or those with higher STOFHLA score have lower prevalence of uncontrolled HbA1c, while those with longer T2DM onset have higher prevalence of uncontrolled HbA1c. Future interventions should focus on younger patients, improve HL, and establish better communications between physicians and patients with T2DM for better glycemic control. (c) 2021 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.