Abstract: Objective To investigate whether the lung immune prognostic index (LIPI) is associated with the clinical efficacy and outcomes of advanced gastric cancer patients treated with immune checkpoint inhibitors (ICIs). Methods Clinical data about 72 patients treated with ICIs in the first and second medical center of Chinese PLA General Hospital from May 2015 to December 2018 were analyzed retrospectively.The cut-off value of neutrophils/(leukocytes minus neutrophils) ratio (dNLR) was calculated by ROC curve according to the disease control status.Patients were classified into LIPI-good group and LIPI-intermediate/poor group based on cut-off value of dNLR and upper limit of normal range of lactate dehydrogenase (LDH) before treatment.Then the disease control rate,progression-free survival and overall survival were compared between the two groups. Results The average age of the 72 enrolled patients was 60.1 years old,and 35 patients (48.6%) were in the LIPI-good group,and 37 patients (51.4%) were in the LIPI-intermediate/poor groups.Compared to LIPI-good group,the intermediate/poor group had higher rate of disease progression (OR,3.99;95% CI,1.27-12.54;P=0.018).Median OS was 11.6 (95% CI,4.5-18.7) months in good LIPI group,and 5.4 (95% CI,4.2-6.6) months in intermediate/poor group;The median PFS was 7.4 (95% CI,3.4-11.4) months,and 2.7 (95% CI,1.2-4.2) months (P<0.05,respectively).Multivariate COX regresssion analysis showed that intermediate or poor LIPI was independently associated with OS (HR 2.68,95% CI,1.52-4.73,P=0.001). Conclusion The pretreatment LIPI is significantly correlated with worse outcomes for advanced gastric cancer patients treated with ICIs.However,the determination of whether LIPI can screen beneficial patients still needs to be further confirmed through studies with large sample size and prospective clinical trials.