Background Triglyceride Glucose index (TyG) was associated with an increased risk of cardiovascular events. Silent coronary disease is common in patients with type 2 diabetes. In Vietnam, a low-middle income country, the burden of cardiovascular disease is growing in parallel to the epidemiologic transition. The aim was in patients with type 2 diabetes and no history or symptom of cardiovascular disease, to assess the prevalence of coronary stenoses (CS) and investigate the association between TyG and cardiovascular risk factors and the presence and severity of CS. Methods We recruited 166 patients at Ninh Thuan General Hospital, Vietnam. TyG and HOMA-IR were calculated, and a coronary computed tomography angiography (CCTA) was performed. Results The population was separated according to tertiles of TyG. Patients with highest TyG had higher BMI, waist circumference, total cholesterol, LDL-cholesterol, triglycerides, plasma glucose and HbA1c levels, lower HDL-cholesterol; more of them had a metabolic syndrome and less practiced physical activity (p<0.05 to <0.001). TyG correlated with HOMA-IR (p<0.001). CS ≥50% were present in 60 patients, with a coronary artery narrowing ≥70% in 32 of them. The patients with CS had higher TyG (p<0.05). The association of TyG with CS remained significant in a multivariate analysis including confounding risk factors. The number of narrowed vessels and the degree of stenosis were associated with higher TyG levels (p=0.04 and <0.005). TyG was significant in identifying patients with CS with an area under the ROC curve of 0.678 (95%CI: 0.582-0.775, p=0.002), a cut-off point of 9.63 offering 75% sensitivity and 44% specificity. In subgroup analysis the association TyG-CS was stronger in patients ≥60 yrs, with HbA1c≥7%, on statin or anti-platelet therapy. The AROC was higher with the triple criterion age-HbA1c-TyG than with age or HbA1c alone (p<0.001 for both comparisons). Conclusion More than one third of asymptomatic patients with type 2 diabetes had CS on CCTA. TyG may be considered as a marker of insulin resistance and allows to identify patients with high risk of coronary stenoses, particularly in those ≥ 60 yrs with poor glycemic control, and is associated with the number and the severity of narrowed branches.