Objective: To investigate the relationship between coronary lesions and AB0 blood groups in patients with acute coronary syndrome who underwent coronary angiography, and to recommend more frequent follow up in cardiology outpatient clinics for lesion specific blood groups. Material and Method: Patients who underwent coronary angiography in the coronary intensive care unit of the cardiology clinic between January 1, 2022 and April 31, 2022 were included in this study. The blood groups of the patients and the cardiovascular lesions detected in coronary angiography were recorded. A lesion with a stenosis of 50% or more in any coronary artery was recorded as significant stenosis. Results: A total of 223 patients were included in our study. Of these patients, 64 (28.69%) were female and 159 (71.31%) were male. The number of patients with Rh (+) blood group was 191 (85.65%), more than the number of patients with Rh ( ) blood group. 42.6% of the patients had A Rh (+) blood group. The mean age of the patients was 63.96, the minimum value was 25.00, and the maximum value was 90.00. 48.2% of the patients had coronary artery disease, 68.5% had hypertension, 40.5% had diabetes. 56.8% of the patients had a lesion in the left anterior descending artery, 11.2% There was a lesion in the diagonal of the left anterior descending, 44.8% had a lesion in the circumphylex artery, and 47.7% had a lesion in the right coronary artery. Conclusion: There was no statistically significant difference between the distribution of coronary lesions according to blood groups (p>0.050). As a result, more research is needed especially on the molecular level of ABO blood groups and their relationship with various diseases. There is a need for new studies in larger study series to determine whether the relationship between blood group antigens and coronary lesions is blood group specific lesion.