Initial management of severe acute pancreatitis (SAP) is conservative. As a step-up approach, percutaneous catheter drainage (PCD) with saline irrigation is reported to be effective. Factors leading to surgery are unclear. In this ongoing prospective study, 70 consecutive patients with SAP were recruited. As a step-up approach, all patients initially received medical management and later underwent PCD and surgery as per the indication. Of the 70 consecutive patients with SAP, 14 were managed medically, 29 managed with PCD alone, whereas 27 required surgery after initial PCD. Sepsis reversal was achieved with PCD alone in 62.5%. The curative efficacy of PCD alone was in 27 patients (48%). Overall mortality in the whole group was 24%. On univariate analysis, factors significantly affecting surgical intervention included initial acute physiology and chronic health evaluation (APACHE) II score, APACHE II score at first intervention, sepsis reversal by PCD within a week, number of organs failed, organ failure within a week of the onset of disease, number of bacteria isolated per patient, renal failure, respiratory failure, Escherichia coli, computerized tomography severity index score at admission, parenteral nutrition requirement before or after radiological intervention, maximum extent of necrosis of more than 50% of the pancreas, and extrapancreatic necrosis. On multivariate analysis, renal failure (P = -0.03), APACHE II score at first intervention (P = -0.006), and the number of bacteria isolated per patient (P = -0.01) remained independent predictors of surgery. An APACHE II score of more than 7.5 at first intervention (PCD) had the ability to predict surgery with a sensitivity of 88.9% and a specificity of 69%. PCD reversed sepsis in 62% and avoided surgery in 48% of the patients. Reversal of sepsis within a week of PCD, APACHE II score at first intervention (PCD), and organ failure within a week of the onset of disease could predict the need for surgery in the early course of disease.