Background: Smoking is widely recognized as a signifi-cant risk factor for acute coronary syndrome (ACS), not only in young patients but across the general population. The risk is further heightened by the use of other smoking products such as cannabis and water pipe smoking (hookah). Aim of Study: The aim of this study is to evaluate the as-sociation between smoking, as an independent risk factor for cardiovascular disease, and angiographic findings in young in-dividuals diagnosed with acute coronary syndrome. Patients and Methods: This retrospective study involved a cohort of one hundred young patients who were smokers and presented with ACS, including both ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarc-tion (NSTEMI), at Alexandria University Hospitals over a thirty nine-monthperiod. The smoking index was calculated to classify the smokers. Results: This research involved 100 patients diagnosed with ACS with a history of smoking, most of whom were male (98%), with a mean age of 38.8±4.5 years. A high smoking in-dex was found in 65% of the patients, who developed STEMI. Regarding the type of smoking, 70% of patients smoked ciga-rettes only, 7% smoked cigarettes with cannabis, 15% smoked cigarettes with water pipe smoking (hookah) and finally, 8% of patients smoked cigarettes with both cannabis and water pipe smoking (hookah). Patients with a high smoking index exhib-ited a higher prevalence of ACS. STEMI was predominant, ac-counting for 82% of cases, while NSTEMI constituted 12%. Angiographic data revealed that 94% of patients underwent stent placement, while 6% had normal coronary angiography. Among the diseased vessels, single vessel disease was more common compared to multivessel disease, with the left anterior descending (LAD) artery being affected in 51% of cases. A sta-tistically significant association was observed between smoking index and the type of myocardial infarction (MI) (p=0.012). Conclusion: Cigarette smoking is a major contributing factor in the pathogenesis of ACS. The risk of ACS is further elevated when cigarette smoking is combined with the use of water pipe smoking and cannabis. Patients with a higher smok-ing index exhibited greater severity of ACS than those with a lower smoking index. Therefore, calculating the smoking index is crucial for classifying patients as mild, moderate, or heavy smokers.