BACKGROUND: In our study, it was aimed to fi nd out whether it would be possible to determine the disease severity by comparing the values of red cell distribution width (RDW), c-reactive protein (CRP), CRP/albumin, neutrophil/lymphocyte ratio (NLR), and platelet/lymphocyte ratio (PLR) in patients with acute pancreatitis according to Bedside Index of Severity in Acute Pancreatitis (BISAP) scores at the time of admission. METHODS: Five hundred patients diagnosed with acute pancreatitis were included in the study. RESULTS: According to BISAP scores, 388 (77.6 %) patients were evaluated as having mild acute pancreatitis and 112 (22.4 %) patients as having severe acute pancreatitis. In ROC analysis, values of 70.54 % sensitivity and 70.10 % specifi city for CRP, 71.43 % sensitivity and 70.88 % specifi city for CRP/albumin, 80.36 % sensitivity and 30.30 % specifi city for RDW, 75.00 % sensitivity and 43.98 % specifi city for NLR, and 55.36 % sensitivity and 38.51 % specifi city for PLR were determined. Values of 85.71 % sensitivity and 66.49 % specifi city were determined for the NLR-CRP/Albumin-RDW 2** score as a newly created scoring system. CONCLUSION: CRP/albumin, NLR, PLR, and RDW values were found to be statistically signifi cantly higher in patients with severe acute pancreatitis compared to those with mild acute pancreatitis according to the BISAP score (p<0.001). In comparison to previous studies in the literature, similar sensitivity and specifi city values were obtained in determining the severity of the disease with the new NLR-CRP/Albumin-RDW 2** score, and it is thought that this scoring system could be a practical and reliable guide in the treatment and follow-up of patients with acute pancreatitis