Background: Ischaemia or infarction occurring due to Coronary Artery Disease (CAD) causes left ventricular systolic and Diastolic dysfunction (DD). DM speeds up the process of coronary atherosclerosis as well as functional and structural cardiac impairments, exhibiting DD at the early stages. Severity of CAD is best assessed by coronary Angiography (CAG). Early diagnosis of this condition is warranted as the mortality risk from it is high. The objective of this study was to detect the CAD in diabetic chronic stable angina with grade IV DD. Material and Methods: 74 Diabetic patients with chronic stable angina with grade-IV diastolic dysfunction were included in this cross-sectional observation study which was done in department of Cardiology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from July 2023 to June 2024. Results: 32 (43.24%) subjects in rural and 42 (56.75%) subjects in urban areas. Proportion of males was 55%. Mean age of study population was (43 + 4.50) years. Mean age(57+7.0 vs 40+8.21years) in rural was significantly higher than urban subjects. 69 (51.06%) were SOB, 26 (19.24%) were tachycardic, 14 (10.36%) had bradycardia, 59 (43.66%) had hypotension, 21(15.54%) had raised JVP, 19(14.06%) had basal crepitation, 19(14.06%) had dependent oedema, 7(5.18%) had hepatomegaly and only 6(4.44%) had Ascites. Most of the dyspneic patients were in NYHA III stage. Around 30% patients were right dominant coronary artery. Most patients had significant stenosis in both LAD and LCX. About one third patients had insignificant stenosis in RCA. Conclusion: There is a relationship between coronary artery disease and Grade IV DD.