Background The Global Leadership Initiative on Malnutrition (GLIM) recently developed a new set of diagnostic criteria for identifying patients with malnutrition. Because the GLIM criteria were only introduced a little over 3 years ago, additional validation and reliability testing are needed in a variety of populations. Methods We performed an observational, multicenter cohort study. From July 2013 to October 2018, lung cancer patients were recruited from the Daping Hospital of Army Medical University and the First Hospital of Jilin University as part of the INSCOC project. Previously-established cut-off values for the calf circumference (CC, male < 30 cm, female < 29.5 cm) were applied as the reduced muscal mass of phenotypic criteria to establish the GLIM diagnosis. Multivariate Cox regression analyses were performed to analyze the association between the GLIM criteria and survival. Results A total of 1219 patients with lung cancer were studied as subjects. Their age was 58.81 ± 9.92 years old, and 820 were male and 399 were female. According to the GLIM diagnostic criteria using the CC as a muscle mass measurement, 303 patients (24.9％) were categorized as malnourished, 142 patients (23.1％) in the adult group (18 ≤ age < 60) and 161 patients (26.7％) in the older group (age ≥ 60 years). The patients with malnutrition had a higher incidence of anemia than the nourished patients (P = 0.012). The QLQ-C30 score and KPS score indicating that the malnourished patients had a consistently worse quality of life compared to the nourished group (all P < 0.001). The median survival of the malnutrition group was 42 (95％ CI: 34-50) months, which was much shorter than the 62 (95％ CI: 57-66) months in the nourished group (P < 0.001). In the adult group, the median survival decreased from 65 (95％ CI: 55-72) months in nourished group to 34 (95％ CI: 25-48) months in the patients with malnutrition (P < 0.001). In the older group, it decreased from 61 (95％ CI: 55-67) months to 48 (95％ CI: 39-59) months (P = 0.001). A Cox regression analysis showed that GLIM-diagnosed malnutrition was associated with an increased risk of death among adult group (HR = 1.670, 95％ CI: 1.29-2.16), older group (HR = 1.332, 95％ CI: 1.05-1.69) and overall (HR = 1.453, 95％ CI: 1.22-1.72). Conclusion All of these results demonstrate that GLIM-diagnosed malnutrition is associated with a poorer survival for all lung cancer patients, independent of age.