Background: PNI has been described as a simple and objective indicator of negative outcomes not only in chronic conditions like hepatocellular carcinoma, chronic heart failure and various cancer types, but also in acute illnesses like acute coronary syndrome, acute heart failure and stroke. To the best of our knowledge, no research has looked at the potential usefulness of PNI for CCU patients. The aim of the study was to assess the correlation between prognostic nutritional index and short-term clinical outcome in terms of mortality in patients of acute heart failure. Methods: This prospective observational study was conducted in the department of Medicine, for a duration twenty-four months among patients hospitalized in department of Cardiology diagnosed as acute heart failure. PNI was calculated by using the formula= [10 x serum albumin(g/dl) + 0.005 x Total lymphocyte count(/mm3 )]. The patient was followed up for 28 days after discharge. The results were analysed using descriptive statistics and making comparisons among various groups. The ROC was analysed to find optimum cut off of PNI for prediction of mortality. Results: In present study 70 patients were enrolled during defined study period. The mean age of the study cases was 55.47±11.05 years. Out of 70 cases, majority 58.6% suffered with type HFmrEF, followed by HFpEF (27.1%) while type HFrEF was diagnosed in 14.3% cases. Out of 70 admitted cases, 67 (95.7%) were survived while 3 (4.3%) were expired. The PNI level was maximum in HFrEF type (48.4±6.4) and minimum in HFmrEF type (45.0±6.0). However no significant difference was found in PNI among various types of heart failure (p=0.214).The ROC analysis to find optimum cut off of PNI for prediction of mortality resulted an optimum cut off as PNI<45.04, which had the sensitivity 100% and specificity 64.18%. It concludes that all themortalities had PNI score less than 45.04, however 64.18% (95% CI 52.95% - 75.41%) survived cases had PNI more than 45.04. Conclusion: Nutritional management, may improve clinical outcomes while reducing hospitalization and medical costs, particularly in older patients with HF. As a result, for risk classification and therapeutic treatment of HF, a clinically meaningful nutritional index is recommended. PNI, which is clinically and easily accessible, was found to be an independent risk factor for cardiovascular death and overall mortality in patients with AHF who had either HFrEF or HFpEF in this investigation.