Aim: A prospective study of the bedside index for severity in acute pancreatitis (BISAP) score in predicting severity and prognosis of acute pancreatitis. Methods: The present prospective study was conducted in the Gastroenterology division of Department of General Medicine at Ananta Institute of Medical Sciences & Research Center, Udaipur, Rajasthan, India for the period of 1 year from December 2021 to November 2022. The total number of patients included in the study was 50. Individual components of the BISAP scoring system were BUN >25mg/dl, impaired mental status (Glasgow Coma Scale Score <15) and SIRS (systemic inflammatory response syndrome). Results: Out of 50 patients, 45 (90%) were males and 5 (10%) were females. Thus, a male preponderance was observed in this disease. Out of 50 patients, 40 had BISAP score <2. Among them, 37 patients (92.5%) had a hospital stay for ≤7 days and only 3 patients (7.5%) had a hospital stay for >7 days. 10 patients had BISAP score >2. Among them, 9 patients (90%) had a hospital stay for >7 days and only 1 patient (10%) had a hospital stay for ≤7 days. Hence, BISAP Score >2 was associated with prolonged hospital stay. In this study, BISAP score had a sensitivity of 70%, specificity of 92.5%, positive predictive value of 70%, negative predictive value of 92.5%, false positive rate of 7.5% and false negative rate of 30% in predicting severe acute pancreatitis and poor prognosis. Conclusion: It is possible to draw the conclusion that the BISAP score accurately predicts the severity of acute pancreatitis as well as the patient's prognosis.