Abstract Aims This study sought to evaluate the correlation between waist‐to‐height ratio (WHtR) and heart failure (HF) outcomes across different ejection fraction (EF) categories. Methods and results A prospective cohort study was conducted at a comprehensive tertiary hospital in China. The participants were categorized by WHtR and EF quartiles. Outpatient or telephone follow‐up occurred every 6 months after the diagnosis of heart failure. The primary endpoint was all‐cause mortality at 48 months. Cox proportional hazard regression analyses were employed to evaluate the association between WHtR and all‐cause mortality. Among 859 enrolled participants, 545 (63.4%) were male, and the mean age was 65.2 ± 11.1 years. After adjusting for age and sex, WHtR demonstrated a strong correlation with both BMI (correlation = 0.703, P = 0.000) and WHR (correlation = 0.609, P = 0.000). Individuals with a high WHtR (≥0.50) had a higher prevalence of hypertension (56.4% vs. 39.6%) and diabetes (26.5% vs. 13.7%), higher levels of TC (3.61 ± 1.55 vs. 3.36 ± 0.90 mmol/L), TG (1.40 ± 0.81 vs. 1.06 ± 0.59 mmol/L), and LDL‐C (2.03 ± 0.85 vs. 1.86 ± 0.76 mmol/L) compared with patients with low WHtR (<0.50). NT‐proBNP levels were inversely correlated with EF values in both low and high WHtR groups. A total of 149 (18.9%) patients died at the conclusion of the follow‐up period. The incidence of all‐cause and cardiovascular death was higher in the low WHtR group compared with the high WHtR group [HRs = 1.83 (1.30–2.58), 1.96 (1.34–2.88), respectively]. There was no significant difference in noncardiovascular mortality or rehospitalization rates between the two groups. Patients with HFrEF/low WHtR exhibited a markedly elevated risk of all‐cause mortality [HR = 2.31; (95% CI: 1.24–4.30)], heart failure mortality [HR = 3.52; (95% CI: 2.92–8.80)], and noncardiovascular mortality [HR = 4.59; (95% CI: 1.19–17.76)] compared with patients with HFrEF/high WHtR. WHtR has a negligible effect on the risk of all‐cause and cardiovascular mortality in heart failure patients with preserved EFs. Conclusions The obesity paradox, as delineated by WHtR, is observed in patients with HFrEF, yet absent in those with HFpEF.