Background and objective:Acute pancreatitis is the acute reversible inflammation of pancreatic parenchyma ranging from mild inflammation with minimal local and systemic effects to severe necrosis of the pancreatic tissue and multi organ failure. Early assessment of severity and early prediction of the risk of morbidity and mortality is the key to proper and timely management. Over the last decade, Red Cell Indices especially Red Cell Distribution Width or RDW has emerged as a marker of acute inflammation and has been used as a predictor of mortality and morbidity in acute pancreatitis. This study was conducted to assess the predictive value of RDW in determining the severity of acute pancreatitis and also to assess its prognostic value in determining acute pancreatitis mortality, multi organ failure and ICU admission in Pakistani population. Methods and Material: 110 patients presenting to surgical ER of Holy Family Hospital Rawalpindi with acute pancreatitis (diagnosed on the basis of raised serum lipase) were retrospectively included in the study. CTSI or CRP levels were used as gold standard to assess severity of acute pancreatitis. RDW levels at admission were recorded for all patients. ROC curves were used to assess the predictive value of RDW in determining the severity, morbidity and mortality related to acute pancreatitis. Results: A positive correlation was found between RDW levels and no. of days of ICU stay (r=0.230, p=0.019). On the ROC curve, RDW only weekly predicted the severity of acute pancreatitis with area under curve of 0.659. At a cut off value of 15.25, RDW predicted severe pancreatitis with a sensitivity of 71.4% and specificity of 56.8%. RDW is a better predictor of acute pancreatitis severity and mortality in men. At a cutoff score of 15.25 RDW predicted mortality with a sensitivity of 100% and specificity of 61.8%, with AUC of 0.735 on the ROC curve. Conclusion is a reliable predictor of acute pancreatitis severity and mortality. Key Words: Red cell indices, RDW, acute pancreatitis