BACKGROUND: The impact of systemic immune inflammatory markers to predict survival in patients receiving neoadjuvant therapy for borderline resectable pancreatic cancer has not been sufficiently investigated. This study aims to evaluate whether systemic immune inflammatory markers after neoadjuvant therapy followed by pancreatectomy become preoperative prognostic factors to predict survival in patients with borderline resectable pancreatic cancer. METHODS: We retrospectively reviewed 67 borderline resectable pancreatic cancer patients receiving neoadjuvant therapy and 58 borderline resectable pancreatic cancer patients undergoing upfront surgery between 2010 and 2016. The association between survival and systemic immune inflammatory markers was evaluated by univariate and multivariate analysis. The neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, and prognostic nutrition index were assessed as systemic immune inflammatory markers. RESULTS: In univariate analysis, the postneoadjuvant neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, and prognostic nutrition index are significantly associated with survival as systemic immune inflammatory markers. The optimal cutoff value of the postneoadjuvant neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, and prognostic nutrition index were 2.5, 3.0, and 45, respectively. Patients with a lymphocyte-to-monocyte ratio <3.0 had significantly poor survival compared with those who had a lymphocyte-to-monocyte ratio ≥3.0 (14.9 months vs 31.7 months, P = .006). The multivariate analysis identified the following as predictors of poor prognosis: postneoadjuvant lymphocyte-to-monocyte ratio <3.0 (HR 2.59; 95% CI 1.02-6.58; P = .045), T4 (HR 1.82; 95% CI 1.11-3.01; P = .029), lymph node status (HR 2.62; 95% CI 1.24-5.51; P = .012), and no completion of adjuvant therapy (HR 7.09; 95% CI 3.08-16.4; P < .001). CONCLUSION: A low lymphocyte-to-monocyte ratio after neoadjuvant therapy is useful prognostic information for patients with borderline resectable pancreatic cancer. This result might indicate a potential role of lymphocyte-to-monocyte ratios in stratification of treatment strategy in borderline resectable pancreatic cancer patients.