Background: Suicide is a major health concern, especially in South Korea. The probability of dying by suicide and the fatality rate differ between men and women. The present study compared the suicide characteristics of women and men and analyzed the choice of suicide methods. Methods: This study retrospectively analyzed patients who visited the emergency department after a suicide attempt in the period from 2016 to 2018, which had been obtained from the National Emergency Department Information System. Variables included suicide methods, Korean Triage and Acuity Scale level, vital signs, and disposition following emergency care. Results: A total of 88,495 (54.7% women vs. 45.3% men) cases were investigated. Significant gender differences were observed in clinical outcomes. In total, 10.3% of the men (n = 3811) and 4.0% of the women (n = 1852) died in the hospital. Women were proportionately more likely to use poisoning (62.3% vs. 51.0% in men) and piercing and cutting (24.9% vs. 22.9% in men) compared with men, whereas men were more likely to use hanging (9.5% vs. 4.6% in women) and being struck (7.9% vs. 1.1% in women). Conclusions: Women chose less lethal suicide methods, whereas men chose more violent methods. The fatalities among men were higher, even when the same method was used. In establishing a suicide prevention policy, it is important to consider gender differences.