The rate of hospitalization for acute coronary syndrome (ACS) among young patients is increasing. Healthcare disparities remain unsolved among female patients. We explored gender differences regarding risk factors, clinical presentation, in-hospital treatment, and long-term outcomes among ACS patients. A total of 445 patients with very early ACS (men ≤ 35 years and women ≤ 40 years of age) were followed for a median of 5 years. Primary clinical endpoint was the composite of cardiac death, non-fatal myocardial infarction, stroke, and coronary revascularization. Women accounted for 16% of cases. Smoking was the most prevalent risk factor, 56% and 60% of the females and males, respectively, continued to smoke after ACS. Chest pain was typical in 85% and 83% of the female and male patients, respectively. In-hospital treatment (pharmacological and reperfusion) as well as the composite clinical endpoint during follow-up did not differ between female and male patients. Lipid-lowering therapy was suboptimal in both genders, and persistence of smoking was the sole predictor for the composite clinical endpoint (hazard ratio: 2.30 [95% CI: 1.26–4.20]; P = .007). In conclusion, in-hospital treatment was similar between male and female patients. However, the majority of them continued smoking, and this was an independent predictor for future adverse outcomes.