Abstract: Background: Neurohormonal activation, congestion and low-grade inflammation are hallmarks of Chronic Heart Failure (CHF). The association between periodontitis and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with stable CHF is not well established. Objective: To assess the relationship between Periodontal Inflammatory Burden (PIS) measured as Periodontal Inflamed Surface Area (PISA) and serum levels of NT-proBNP in adults with stable CHF. Methods: A cross sectional study was conducted with 120 dentate CHF patients aged 40–75 years who attended a cardiology outpatient clinic. Full mouth periodontal examination was performed to record probing pocket depth, clinical attachment level, recession, bleeding on probing and PISA. NT-proBNP and high-sensitivity C-reactive protein (hs-CRP) were measured on the same day. Patients were divided into low ( < 400 mm2), moderate (400–899 mm2) and high ( > 900 mm2) PISA burden groups. Results: The mean age was 61.8 ± 9.7 years, 68 patients (56.7%) were male and 63 (52.5%) had heart failure with reduced ejection fraction. Mean PISA was 684 ± 402 mm2 and mean NT-proBNP was 1705 ± 1056 pg/mL. NT-proBNP increased progressively across low, moderate and high PISA groups (1038 ± 522, 1587 ± 702 and 2476 ± 1230 pg/mL, respectively; p < 0.001). PISA correlated positively with NT-proBNP (r = 0.48, p < 0.001) and hs-CRP (r = 0.44, p < 0.001). PISA was independently associated with log10 NT-proBNP after adjustment for age, sex, BMI, smoking, diabetes, renal function, LVEF, heart failure phenotype and NYHA class (β = 0.024 per 100 mm2; 95% CI: 0.009–0.039; p = 0.002). Conclusion: NT-proBNP levels were independently related to greater periodontal inflammatory burden in stable CHF patients. In a multidisciplinary approach to CHF, periodontal assessment may offer more information about inflammation.