The present study aimed to evaluate sex-specific association between admission systolic blood pressure (SBP) and in-hospital prognosis in patients with acute decompensated heart failure (ADHF) admitted to intensive care unit (ICU). In this retrospective, observational study, 1268 ADHF patients requiring intensive care were consecutively enrolled and divided by sex. Patients were divided into three subgroups according to SBP tertiles: high (≥ 122 mmHg), moderate (104–121 mmHg) and low (< 104 mmHg). The primary endpoint was either all-cause mortality, cardiac arrest or utilization of mechanical support devices during hospitalization. Female patients were more likely to be older, have poorer renal function and higher ejection fractions (p < 0.001). The C statistics of SBP was 0.665 (95%CI 0.611–0.719, p < 0.001) for men and 0.548 (95% CI 0.461–0.634, p = 0.237) for women, respectively. Multivariate analysis demonstrated that admission SBP as either a continuous (OR = 0.984, 95% CI 0.973–0.996) or a categorical (low vs. high, OR = 3.293, 95% CI 1.610–6.732) variable was an independent predictor in male but the risk did not statistically differ between the moderate and high SBP strata (OR = 1.557, 95% CI 0.729–3.328). In female, neither low (OR = 1.135, 95% CI 0.328–3.924) nor moderate (OR = 0.989, 95% CI 0.277–3.531) SBP had a significant effect on primary endpoint compared with high SBP strata. No interaction was detected between left ventricular ejection fraction (LVEF) and SBP (p for interaction = 0.805). In ADHF patients admitted to ICU, SBP showed a sex-related prognostic effect on primary endpoint. In male, lower SBP was independently associated with an increased risk of primary endpoint. Conversely, in female, no relationship was observed.