Heart failure (HF) is a complex clinical syndrome associated with increased disability, morbidity and mortality globally. HF is characterized by recurrent exacerbations and a high rate of hospital readmissions. Self-care is a crucial component of treatment. The way patients assess the importance of self-care may shed light on planning effective individualized interventions. The aim of this study was to conduct a validity and reliability analysis of the new 14-item IPSC scale, which measures how important HF patients consider their physical self-care behavior (IPSC, Importance of Physical Self-Care). The 14-item IPSC scale was created by the researchers to explore how important HF patients consider their physical self-care behavior. The validation of the IPSC scale included face and content validity, construct validity, internal consistency, repeatability and discriminant validity. Patients' characteristics were also included. In the present study, 52 hospitalized HF patients were enrolled, of whom 55.8% were female, 34.6% above 70 years old, 48.1% of NYHA class III and 32.7% suffered this illness from 6 to 10 years. The total IPSC score had a possible range of 14-56, with higher scores indicating a low importance of self-care. The descriptive statistics in the IPSC scale showed a mean score of 27.9 ± 4.9 and a median score of 29, indicating that HF patients evaluated self-care behavior as moderately important. All items were found to be statistically significantly correlated with total scale scores (p ≤ 0.05), with correlation coefficients rho > 0.250, indicating moderate to strong correlations and meaning that all items are important in the calculation of the final score (construct validity). The internal consistency of the items that constituted the total score was found to be high (Cronbach's a > 0.7). Furthermore, it was found that scores had high repeatability (p ≤ 0.001 and ICCs > 0.7). Regarding discriminant validity, a statistically significant association was observed between the importance of physical self-care behavior and both years suffering the illness (p = 0.007) and the NYHA class (p = 0.030). The 14-item IPSC scale is a reliable instrument that help nurses in clinical settings to gain a better and prompt understanding of the importance which patients invest in their physical self-care behavior.