Aim    The Naples prognostic score (NPS) simultaneously evaluates inflammation and malnutrition, which are two main factors that play a role in the pathophysiology and prognosis of heart failure (HF). In this study, we aimed to examine the relationship of NPS with in-hospital mortality of hospitalized patients with a diagnosis of HF.Material and Methods    A total of 496 hospitalized HF patients included in this study. The patients were divided into two groups as deceased and living. The clinical and demographic characteristics of each patient were recorded. NPS of each patient was calculated.Results    NPS was significantly higher in the deceased group compared to the living group (3.6±0.61, 3.21±0.97, respectively; p=0.003). According to multivariate regression analysis: NPS (OR: 1.546, 95 % CI: 1.027–2.327; p=0.037), systolic blood pressure (OR: 0.976, 95 % CI: 0.957–0.995; p=0.015), and white blood cell count (OR: 1.072, 95 % CI: 1.007–1142; p=0.03) are independent predictors for in-hospital mortality in HF patients.Conclusion    This study demonstrated a strong correlation between NPS and mortality in HF. This new score can be used to predict the prognosis of HF as it shows both the level of inflammation and nutrition.