In patients with acute decompensated heart failure (HF), the influence of gender on anemia, left ventricular ejection fraction (EF), and outcomes is unclear. We evaluated the association of anemia and left ventricular EF with survival in men or women hospitalized for acute decompensated HF. Of the 4,842 patients enrolled in the Acute Decompensated Heart Failure Syndromes registry, 4,215 patients (2,450 men and 1,765 women) discharged alive after hospitalization for acute decompensated HF were enrolled to evaluate the association of gender, anemia (hemoglobin <13.0 g/dl for men and <12.0 g/dl for women) at discharge, and a preserved or reduced EF with all-cause death or cardiac death after discharge. Men or women were divided into 4 groups based on left ventricular EF (preserved or reduced EF) and anemia status at discharge. The median follow-up period after discharge was 524 days (384 to 791). After adjustment for multiple co-morbidities, there was no adverse influence of anemia in men with a preserved EF, whereas anemia was an independent predictor of all-cause death in men with a reduced EF. Conversely, anemia was an independent predictor of all-cause death in women with a preserved EF but not in women with a reduced EF. With respect to cardiac death, multivariable analyses revealed highly similar trends as those for all-cause death in patients of both genders. In conclusion, in acute decompensated patients with HF with a preserved or reduced EF, there were marked differences between men and women with respect to the association of anemia and left ventricular EF with survival.