The purpose of this study was to investigate the clinical value of Global Leadership Initiative on Malnutrition GLIM criteria and evaluate the relationship between GLIM-defined malnutrition and survival outcome of gastric cancer patients. Method Totally 174 gastric cancer patients who underwent radical resection at the Department of Gastrointestinal Surgery in our hospital from January 2017 to December 2021were selected as the research participants. Body mass index BMI and the third lumbar skeletal muscle index SMI were used as phenotypic criteria of GLIM consensus for the evaluation of nutritional status and the diagnosis of malnutrition. The effects of GLIM-defined malnutrition on the prognosis of gastric cancer patients were estimated by KaplanMeier method and the univariate and multivariate Cox regression analysis. Result Nutritional risk screening at admission showed that 80 46. 0% of 174 gastric cancer patients were at risk of malnutrition NRS 2002 ≥3 . According to the GLIM criteria it was found that 57 32. 8% of 174 gastric cancer patients were diagnosed with malnutrition before surgery and low BMI was observed in 24 13. 8% patients and reduced muscle mass was observed in 51 29. 3% patients. BMI 20. 4 ± 2. 5 vs 23. 5 ± 3. 4 kg / m 2 t = 6. 093 P<0. 001 SMI 37. 9 ± 4. 2 vs 46. 2 ± 7. 9 cm 2 / m 2 t = 7. 424 P<0. 001 hemoglobin concentration 125. 0 ± 18. 0 vs 136. 0 ± 20. 0 g / L t = 3. 333 P= 0. 001 and serum albumin level 36. 7 ± 4. 6 vs 39. 0 ± 3. 9 g / L t = 2. 470 P= 0. 014 were significantly lower in patients with GLIM-defined malnutrition than in those without malnutrition. Survival analysis indicated that the 5-year disease-free survival DFS rates of patients with and without malnutrition based on the GLIM criteria were 49. 8% and 75. 6% respectively χ 2 = 7. 502 P = 0. 006 . Subgroup analysis showed that GLIM - defined malnutrition was significantly associated with worse DFS of stage Ⅲ patients. The 5 -year DFS rates of patients with and without malnutrition were 31. 7% and 69. 2% with a significantly statistical difference χ 2 = 12. 523 P<0. 001 . In addition the univariate and multivariate Cox regression analysis demonstrated that GLIM - defined malnutrition HR = 2. 180 95% CI = 1. 288 - 3. 687 P = 0. 004 TNM stage HR = 2. 216 95% CI = 1. 245 - 3. 947 P = 0. 007 and Borrmann classification HR = 2. 171 95% CI = 1. 019 - 4. 624 P = 0. 044 were independent prognostic factors for gastric cancer patients. Conclusion GLIM criteria could reflect the nutritional status of gastric cancer patients and it could be used as an effective tool for prognostic assessment.