ObjectiveTo investigate the clinical value of the C-reactive protein (CRP) ratio (CRP value on postoperative day 3/day 1) as an early predictor of postoperative severe complication after laparoscopic gastrectomy (LG) for gastric cancer.MethodsThis retrospective study examined the relationship between the occurrence of severe complication and the CRP ratio of 259 gastric cancer patients, who underwent LG in the Department of General Surgery of General Hospital of Fuxin Mining Industry Group of Liaoning Health Industry Group from January 2015 to January 2020. According to Clavien-Dindo (CD) grading system, gastric cancer patients were divided into the severe postoperative complication group (n=41, 15.8%) and the non-severe postoperative complication group (n=218, 84.2%). The relationship between CRP ratio and clinicopathologic characteristics of patients and the predictive value of CRP ratio for severe complication were analyzed.ResultsThe optimal cutoff value of CRP ratio of 2.2 offered 63.2% sensitivity, 91.0% specificity, 70.7% positive predictive value, and 85.8% negative predictive value for severe postoperative complication. The area under the receiver operating characteristic curve was 0.766. There had distinct differences (P<0.05) on body mass index, preoperative comorbidity, type of surgery, T stage, and TNM stage between the high CRP ratio group (CRP ratio >2.2, n=60) and the low CRP ratio group (CRP ratio ≤2.2, n=199). Logistic regression showed that preoperative comorbidity [OR=3.624, 95%CI (1.191, 11.206), P=0.023], later of TNM stage [OR=9.037, 95% CI (1.729, 47.226), P=0.009], and CRP ratio >2.2 [OR=20.473, 95%CI (7.948, 52.737), P<0.001] were independent risk factors for postoperative severe complication after LG.ConclusionThere must to be paid enough attention to the CRP ratio >2.2 on the day 1 and 3 after LG, it suggests that there might be a risk of severe postoperative complications.