Background and Aim: Diastolic heart failure is a common yet difficult to identify condition. The study's goal was to investigate and link NT-proBNP levels with four classes (grade I to grade IV) of diastolic dysfunction as measured by echocardiography. All patients underwent a thorough clinical examination, blood biochemistry, electrocardiography, chest X-ray, echocardiography, and plasma NT-proBNP testing. Material and Methods: The current study was carried out on 50 DHF patients enrolled from outdoor and indoor patients in the Department of Medicine, Tertiary Care Teaching Institute of India over a one-year period. Clinical assessment and echocardiography were performed on the patients. The autoanalyzer was used to estimate NT-proBNP utilising the electrochemiluminisense method. Echocardiography was used to classify patients into different levels of diastolic dysfunction. Results: The mean levels of NTproBNP in individuals with systemic hypertension were statistically significant (p0.05) higher than in non-hypertensive patients in the current investigation. NT-proBNP levels were observed to be statistically greater in LVH participants compared to those without LVH. (p≤0.05) In the current study of 50 patients with diastolic heart failure, 36 patients (72%) had grade I diastolic dysfunction, 9 patients (18%) had grade II diastolic dysfunction, 3 patients (6%) had a grade III diastolic dysfunction, and 2 patients (3%) had a grade IV diastolic dysfunction. Conclusion: Serum NT-proBNP levels give reliable diagnostic accuracy for detecting diastolic heart failure, and they correlate well with increasing degree of diastolic dysfunction as measured by a well-established modality of echocardiography. In symptomatic individuals, NT-proBNP can accurately detect the presence of isolated diastolic dysfunction and is a valuable diagnostic for ruling out patients with impaired exercise tolerance of non-cardiac origin.