Abstract: Objective To explore the prognostic value of the neutrophil-to-albumin ratio (NAR) combined with the systemic immune-inflammation index (SII) in advanced pancreatic cancer patients.Methods A total of 194 advanced pancreatic cancer patients who were admitted to Yancheng First People's Hospital from October 2011 to June 2023 were selected ant their clinical data were analyzed. The optimal cutoff values for carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), platelet-to-albumin ratio (PAR), NAR, and SII were determined using X-Tile software. The time-dependent area under the receiver operating characteristic (t-AUC) curves for these indices were plotted using R software. Kaplan-Meier survival curves were drawn, and log-rank tests were used to compare survival rates. Multivariate Cox regression analysis was conducted to identify independent prognostic factors, and a nomogram model was constructed. The discriminative ability and accuracy of the model were evaluated using receiver operating characteristic (ROC) curves and calibration curves.Results The median follow-up time was 22.6 months, and the median survival time was 5.7 months. t-AUC analysis showed that NAR and SII performed better in predicting prognosis for advanced pancreatic cancer, leading to the development of the N-SII score. Multivariate Cox regression analysis identified the following as independent risk factors for advanced pancreatic cancer: primary tumor diamete ＞4 cm (HR=1.398, 95%CI:1.001-1.951), number of metastatic organs ≥2 (HR=1.897, 95%CI:1.030-3.493), no chemotherapy (HR=2.353, 95%CI: 1.711-3.235), CEA ＞8.59 U/mL (HR=1.410, 95%CI:1.008-1.972), and high N-SII score (HR=1.501, 95%CI:1.011-2.231; HR=2.951,95%CI:1.938-4.494). The nomogram model constructed based on the N-SII score and other prognostic factors showed AUC values of 0.775, 0.796, and 0.825 at 3, 6, and 12 months, respectively. The calibration curve demonstrated good accuracy of the model.Conclusions The N-SII score is an independent prognostic factor for survival in advanced pancreatic cancer patients, and the nomogram model based on it can accurately predict patient prognosis.