Background: Limited research has explored sex-specific differences in death predictors of HF patients with ischemic (iCMP) and nonischemic (niCMP) cardiomyopathy. This study assessed sex differences in niCMP and iCMP prognosis. Methods: We studied 7487 patients with HF between February 2017 and September 2020. Clinical features and echocardiographic findings were collected. We used Kaplan–Meier, Cox proportional hazard models, and chi-square scores of Cox regression to determine death predictors in women and men. Results: The mean age was 64.3 ± 14.2 years, with 4417 (59%) males. Women with iCMP and niCMP exhibited a significantly higher mean age, higher mean left ventricular ejection fraction, and smaller left ventricular diastolic diameter than men. Over 2.26 years of follow-up, 325 (14.7%) women and 420 (15.7%) men, and 211 women (24.5%) and 519 men (29.8%) with niCMP (p = NS) and iCMP (p = 0.004), respectively, died. The cumulative incidence of death was higher in men with iCMP (log-rank p < 0.0001) but similar with niCMP. Cox regression showed chronic kidney disease, diabetes, stroke, atrial fibrillation, age, and myocardial infarction as the main predictors of death for iCMP in women and men. Conclusions: Women exhibited a better prognosis than men with iCMP, but similar for niCMP. Nevertheless, sex was not an independent predictor of death for both CMP.