Background: Several preoperative systemic inflammatory parameters, such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and Glasgow Prognostic Score, have been reported to be associated with the prognosis of solid tumors. However, there are conflicting survival data regarding these parameters in cholangiocarcinoma. Objectives: In this study, we performed a retrospective cohort analysis of patients with distal cholangiocarcinoma (DCC) who underwent surgical resection to evaluate the prognostic value of a cluster of preoperative hematological inflammatory parameters for survival. Method: Fifty-three patients with DCC who underwent pancreaticoduodenectomy with curative intent were enrolled. The optimal cutoff values of hematological inflammatory parameters, including the absolute lymphocyte count, NLR, PLR, and LMR, were determined by time-dependent receiver operating characteristic analysis. Results: The univariate analysis for overall survival (OS) of conventional factors and hematological inflammatory parameters identified that portal vein invasion and PLR had p values of ≤0.1. The univariate analysis for disease-free survival (DFS) identified that lymph node metastasis, PLR, lymphocyte count, and number of positive lymph nodes (≥3) had p values of ≤0.1. These factors were incorporated into the full model and variables were selected using the backward stepwise method. The multivariate analysis identified portal vein invasion and high PLR as independent prognostic factors for OS (p = 0.033 and 0.039, respectively) and high PLR and number of positive lymph nodes (≥3) as independent prognostic factors for DFS (p = 0.016 and 0.004, respectively). Conclusions: Preoperative PLR assessment may be useful for detecting high-risk DCC patients undergoing surgical resection for aggressive adjuvant therapy.