We examined the relationship between hematological parameters and clinicopathologic significance in metastatic or recurrent gastric cancer (MRGC) patients, and construct a prognostic index for MRGC patients. We retrospectively reviewed the medical records of 439 patients with MRGC. Tumor markers, inflammation-based markers such as mGPS (which combines CRP and albumin concentrations), NLR, PLR and other hematological parameters were observed in the study. CA125 was more frequently positive with peritoneal recurrence, and CEA was more frequently positive in patients with liver metastases. In the univariate analysis of survival, the following variables were associated with shorter overall survival (OS): male, previous pathology such as nerves invasion and vessel invasion, elevated CEA, CA72-4, CA125 and CA19-9, and inflammation-based variables such as Alb, CRP, mGPS, PLR, NLR, Hb, LDH, AchE and AKP. In the multivariate analysis, mGPS, CEA and CA125 were independent prognostic factors for OS. An exploration of the potential prognostic index model including the three independent factors was carried out, MSTs for the low-, moderate- and high-risk groups were 12, 10.5 and 5 months. Elevated serum CEA, CA125 and mGPS in patients with MRGC are independent negative predictor of prognosis. And the prognostic index was constructed to predict prognosis of MRGC patients more accurately.