Background: Immune function influenced patients' recovery from major abdominal surgery. The aim of this study is to explore the clinical feasibility of peripheral lymphocyte absolute counts for predicting short-term surgical outcomes in gastric cancer patients after laparoscopic D2 gastrectomy. Methods: This is a prospective cohort study from a single tertiary referral hospital. Patients diagnosed with gastric cancer who met the inclusion criteria were included in this study. We collected the demographic and clinicopathological characteristics of included patients. We monitored perioperative dynamics of absolute counts of peripheral lymphocyte subsets. Predictive factors for length of postoperative hospital stay and complications were investigated in univariate and multivariate analyses. Results: A total of 137 gastric cancer patients were included. Decreased preoperative absolute counts of peripheral lymphocyte subsets were correlated with advanced clinical stage. In multivariate analysis, independent predictive factors for prolonged hospital stay were age (p=0.04), decreased preoperative B cell counts (p=0.05), decreased preoperative NK cell counts (p=0.05) and complications (p<0.01). For postoperative complication, independent predictive factors were age (p=0.02), operation time (p=0.05), lymphocyte to C-reactive protein ratio (p=0.01) and decreased preoperative B cell counts (p=0.01). Conclusion: Our findings for the first time revealed that absolute counts of peripheral lymphocyte subsets are independent predictive factors for surgical outcomes in gastric cancer patients after D2 gastrectomy. We suggested that patients with impaired immune state should receive both preoperative immune modulator and nutritional support.