Background: The aim of this study was to assess the association of triglyceride-glucose (TyG) index with glycated haemoglobin (HbA1c) and insulin resistance in type 2 diabetes mellitus (T2DM). Methods:A total of 140 patients with T2DM were included in this cross-sectional study and divided into two groups according to their HbA1c levels: participants with HbA1c <7.0% (n=75) and those with HbA1c >7.0% (n=65) were defined as having a good glycemic control (group I) and a poor glycaemic control (group II) in T2DM. Anthropometric and biochemical parameters were measured, while the values of triglyceride (TG) to high density lipoprotein cholesterol (HDL-C) (TG/HDL-C) ratio and TyG index were calculated using formula. Results: Body mass index (BMI), fasting blood glucose (FBS), HbA1c and homeostatic model assessment for insulin resistance (HOMA-IR) were significantly higher in diabetic patients with poor glycemic control. TyG index was significantly correlated with HbA1c, HOMA-IR, TyG-BMI and TyG-WC. The receiver operating characteristic (ROC) analysis showed that TyG had a maximum area under the curve of 0.806, with a cut off value of 15.5 for identifying glycemic control in diabetic patients. Conclusion:TyG index is a useful tool for assessing glycemic control in T2DM patients and positively correlated with HbA1c and HOMA-IR. Hence, TyG can be used as a simple and inexpensive alternative to assess glycemic control in patients with diabetes.