Background Evidence suggests differences in clinical characteristics, causes, and prognoses between heart failure with reduced ejection fraction ( HF r EF ) and heart failure with preserved ejection fraction (HFpEF). Most studies have failed to support the prognostic relevance of anxiety in HF r EF or unclassified HF with mean left ventricular ejection fraction <40%. Meanwhile, the association between anxiety and prognoses in HF p EF remains unexamined. This study compared the prognostic value of anxiety between HF r EF and HF p EF . Methods and Results A total of 158 patients with HF r EF (left ventricular ejection fraction=28.51±7.53%) and 108 patients with HFpEF (left ventricular ejection fraction=64.53±9.67%) were recruited between May 2012 and December 2014. Demographic and clinical characteristics, Spielberger State‐Trait Anxiety Inventory, Beck Depression Inventory‐ II scale, and 18‐month follow‐up outcomes were recorded during the hospital stay. There were significant differences in age, sex, comorbidities, laboratory biomarkers, discharge medications, and unhealthy behaviors, which supported the contention that HF r EF and HF p EF represent 2 distinct phenotypes, although there were no significant differences in anxiety and 18‐month outcomes. Multiple logistic regression yielded no significant associations between anxiety and 18‐month outcomes in HF r EF . By contrast, trait anxiety could predict 18‐month all‐cause mortality (odds ratio, 1.429; 95% CI, 1.020–2.000; P =0.038), all‐cause readmission or death (odds ratio, 1.147; 95% CI , 1.036–1.271; P =0.008), and cardiac readmission or death (odds ratio, 1.133; 95% CI , 1.031–1.245; P =0.010) in HF p EF after adjusting for possible confounders. Conclusions Trait anxiety was independently associated with 18‐month all‐cause mortality, all‐cause readmission or death, and cardiac readmission or death in HF p EF , but not in HF r EF .