Introduction: Atrial fibrillation (AF) is the most common sustained arrhythmia with an increasing incidence and prevalence in older age groups compared to younger individuals and the general population. Younger patients with AF often have different clinical characteristics, risk factors, and outcomes. Because AF among the young has not been studied in Middle Eastern populations, we conducted this study to provide valuable insights into the differences in the baseline clinical characteristics and the one-year adverse events between young and older AF patients, and thus contribute to formulate future treatment strategies and improve health outcomes. Methods: Consecutive adult patients previously or newly diagnosed with AF in 30 hospitals and out-patient cardiology clinics were enrolled in the Jordan AF study from May 2019 to October 2020. All patients were followed-up for one year. Baseline clinical characteristics and the one-year adverse events were assessed in young (<50 years) and older (≥ 50 years) adult patients with AF. Results: Of the 2020 AF patients enrolled in the study, 201 (10%) were young. Young patients were more likely to be men (75.6% vs. 43.8%, p<0.001), and had a lower prevalence of hypertension (31.3% vs. 79.3%, p<0.001), diabetes mellitus (10.4% vs. 47.2%, p<0.001), and previous stroke (9.0% vs. 16.1%, p=0.027) compared to older patients. Furthermore, young patients had a lower mean CHA ₂DS ₂-VASc score (1.1±1.4 vs. 3.9±1.7, p<0.001) and mean HAS-BLED score (0.6±0.7 vs. 1.8±1.1, p<0.001). The use of oral anticoagulant agents was significantly lower in young patients (39.3% vs. 75.0%, p<0.001). Young patients also had lower one-year all-cause mortality (1.1% vs. 13.7%, p=0.001), cardiovascular mortality (1.1% vs. 7.7%, p=0.04) and major bleeding (0% vs. 2.7%, p=0.021) compared to older patients. The rate of stroke and systemic embolization was similar in both groups (3.4% vs. 4.4%) Conclusion: The findings of the Jordan AF study suggest that young patients (<50 years of age) comprise a small proportion (10%) of the overall AF patient population. They had more favorable baseline clinical characteristics and risk scores compared to older patients. The one-year mortality and major bleeding rates in young patients were also lower than that in older patients.