Acute Coronary Syndrome is one of the leading causes of mortality worldwide. Patients of ACS can present either with STEMI or NSTE-ACS. Many tools and scores were validated for risk stratification. Few studies correlated these risk scores with the anatomical complexity. Methods: This study was conducted on 976 participants with ACS, admitted to the critical care department, Kasr Elainy hospital, Cairo University during the period between January 2015 and December 2019. GRACE, TIMI and ACTION registry GWTG risk scores were calculated and correlated to the SYNTAX score. Results: There was a positive correlation between GRACE, TIMI, AR-G and the SYNTAX score in both STEMI and NSTE-ACS patients. In patients with STEMI, GRACE score (AUC: 0.774, CI: 0.652 – 0.859, P: 0.0001), AR-G (AUC: 0.79, CI: 0.670 – 0.910, P: 0.0001) and TIMI score (AUC: 0.785, CI: 0.675 – 0.896, P: 0.0001) could predict SYNAX score > 32. In NSTE-ACS patients, GRACE score (AUC: 0.831, CI: 0.694 – 0.969, P: 0.001) and AR-G score (AUC: 0.847, CI: 0.734 – 0.960, P: 0.0001) could predict SYNAX score > 32. Residual SYNTAX score was significantly higher in the MACE groups (P: 0.001). Conclusion: The presence of more severe coronary lesion in ACS patients would result into worse clinical presentation. More aggressive management to achieve complete revascularization should be proposed in high risk ACS patients.