Background: Immune function is associated with clinical outcomes in patients with gastric cancer. This study aimed to explore the prognostic role of peripheral lymphocyte subsets in patients with gastric cancer after curative surgery.Methods: This retrospective study was conducted at a single tertiary referral hospital. We included patients diagnosed with gastric cancer who had undergone surgery and met the inclusion criteria. Clinicopathological characteristics and preoperative peripheral lymphocyte subset data were collected for the analysis. Recurrence-free survival (RFS) and overall survival were analyzed using the Kaplan-Meier curve and Cox hazard regression model. We used the Whitney test and Spearman test to analyze the correlation between lymphocyte subsets and clinicopathological characteristics.Results: This study included 171 patients with gastric cancer who underwent curative surgery. Multivariate analysis revealed that carcinoembryonic antigen (p < 0.01), carbohydrate antigen 19-9 (p < 0.001), lymph node metastases (p < 0.001), total T-cell count (p = 0.02), B-cell count (p < 0.01), and regulatory T-cell percentage (p < 0.01) were independent predictive factors associated with RFS. Conclusions: Impaired immune function may lead to early recurrence following curative surgery. Our study showed that the characteristics of peripheral lymphocyte subsets (T, B, and Treg cells) were independent pre-dictive factors for recurrence in patients with gastric cancer after surgery.