Background: The prevalence of coronary artery disease (CAD) in diabetes is not only high, but also characterized by severe disease. The prevalence of CAD in the diabetic population ranges from 9.5% to 55%. SYNTAX is a significant scoring system predicting the prognosis and the need for revascularization. Aim and objectives: to investigate the extent and severity of CAD, assessed with SYNTAX score in patients with T2DM with stable angina pectoris (SAP) compared to non-diabetic. Subjects and methods: This is a single center prospective study conducted at the cardiac catheterization unit at Benha university hospitals from February 2022 to March 2023. Included 150 patients subjected to coronary angiography due to ACS, stable CAD. Results: There was a statistically significant difference between the studied groups regarding SYNTAX score (p˂0.001). There was a statistically significant difference between the studied groups regarding RSWMA (p˂0.001). Conclusion: The SYNTAX score (SS) is significantly associated with burden of coronary artery lesion in T2DM patients having CAD