The rate of POC following PD remains high despite advanced surgical skills and perioperative management [1]. In addition, the mortality rate of PD ranges from 1.7% to 4.2% [17,18]. Rijssen et al. [3] showed that POPF was mainly attributable to worse mortality. Moreover, Linnemann et al. [1] showed that medical costs increased by about 50% after POCs following PD. Thus, adequate prevention or treatment of POPF can contribute to reducing the mortality rate. Accumulating evidence suggests that patient characteristics and perioperative conditions are associated with POPF following pancreatic resection, including higher BMI, soft pancreatic texture, lower serum albumin levels, higher CRP levels, and preoperative nutritional status [19,20,21]. However, a definitive risk factor for POPF has not yet been established. For such occasions, several POPF predictive scores, including inflammatory and/or nutritional status, have been developed, such as the GNRI [4,5], controlling nutritional status score [20], and prognostic nutritional index [22] to detect POPF at an earlier phase and with more precision. In addition, those scores using inflammatory or nutritional status, such as GNRI [23], the platelet-to-lymphocyte ratio [24], and neutrophil-to-lymphocyte ratio (NLR) [25,26], have been designed as prognostic factors in several types of cancers. Moreover, more recent reports have revealed that NLR, CRP-to-lymphocyte ratio (CLR), CAR, and GNRI play a critical predictive role in the incidence of POCs in pancreatic cancer [27,28]. Briefly, Huang et al. [27] revealed that NLR could predict POCs following PD . Fan et al. [28] showed that pretreatment CLR could be considered a feasible biomarker for the prognostic prediction of pancreatic cancer [28]. Actually, nutritional intervention with omega-3 fatty is a recommended strategy for pancreatic cancer patients to reduce POCs [29]. The common perception that the oncological characteristics and patient conditions influence the prognosis of patients with cancer has spread worldwide. In this manner, the clinical effect of novel scores, including nutrition and/or inflammatory indices, has been developed one after another to predict patient outcomes or postoperative complications.Therefore, we evaluated whether the preoperative calculated CAR was associated with the risk of POPF following PD. Fairclough et al. [16] first reported that CAR, which includes CRP and albumin, is a predictive marker of mortality in acute medical admissions. Subsequently, several studies have consistently shown an association between CAR and cancer prognosis [30,31]. For example, Yoshida et al. [30] reported that CAR is associated with long-term outcomes of malignant pleural mesothelioma [30]. Recent evidence also revealed that CAR is a better prognostic factor in lung cancer [31]. Moreover, Zang et al.’s [32] meta-analysis also showed that CAR could be a useful prognostic biomarker in patients with pancreatic cancer who underwent surgery. Recently, Sakamoto et al. [33] showed that CAR on POD 3 is a reliable prediction marker of POPF following PD. This study was the first to prove the association between postoperative CAR and POPF. However, they confirmed the utility of postoperative calculated CAR values on POD3, which was the day for POPF diagnosis utilizing drain amylase level. We believe that preoperative availability is useful in patient risk evaluation and management of the perioperative period for surgeons to reduce the incidence of lethal conditions. Thus, no reports have focused on the association between higher preoperative CAR and the risk of POPF following PD. In this study, a preoperative CAR value of ≥ 0.09 was strongly correlated with the risk of POPF, supporting the clinical significance of preoperative nutritional assessment. This result suggests the clinical effect of nutritional assessment using preoperative CRP and albumin values. Poor preoperative nutritional condition or the presence of inflammation reflected by a lower CAR can affect postoperative recovery, including protracted wound healing. The precise mechanisms underlying the association between lower CAR and POPF should be determined in future studies. Finally, our study had a few limitations when interpreting the results. An important limitation was that this was a retrospective study with a relatively small sample size. Moreover, the data were collected from a single center. Therefore, a more comprehensive prospective study should be conducted in the future to validate our findings.