Purpose: This study aimed to examine the relationships between the N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels with the sociodemographic and clinical factors, self-care behaviors, and the physical symptom experiences in patients with heart failure. Methods: This cross-sectional study utilized a convenience sample of adult outpatients and inpatients who attended a cardiology department in a tertiary hospital in Seoul, Korea. The data from 154 patients with heart failure were collected using a questionnaire, and their clinical data were extracted from their electronic medical records. Results: Compared with the patients with high NT-proBNP levels, those with low NT-proBNP levels had significantly lower physical symptom experiences scores. Patients with low- and mid-NT-proBNP levels were more likely to be employed compared with those with high NT-proBNP levels. Patients with low NT-proBNP levels had higher left ventricular ejection fractions, and were less likely to have arrhythmias and comorbidities. Conclusion: The results from this study showed that patients with more severe heart failure had higher physical symptom experiences scores; hence, individualizing treatment approaches based on heart failure severity is necessary.