BACKGROUND AND OBJECTIVES: Mucinous gastric adenocarcinoma (MGC) is historically linked to poor prognosis, yet literature inconsistencies necessitate systematic evaluation. This meta-analysis aims to compare clinicopathological features and survival outcomes between MGC and non-mucinous gastric adenocarcinoma (NMGC). METHODS: A systematic search (PubMed/Embase/Web of Science, up to April 2024) identified cohort/case-control studies. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated via random-effects models. Subgroup analyses stratified by TNM stage, sample size, geographic region, and T stage were conducted. Heterogeneity, publication bias (Begg’s/Egger’s tests), and sensitivity analyses were assessed. Study quality was appraised using the Newcastle-Ottawa Scale. RESULTS: Twenty-nine studies (163,116 patients; 4,900 MGC) revealed worse univariate overall survival for MGC (HR=1.73, 95%CI=1.48, 2.01), but significance vanished after multivariable adjustment (HR=1.09, 95%CI=0.95, 1.25). Subgroup analyses demonstrated heterogeneity: early-stage MGC (TNM I) had poorer prognosis (HR=1.53, 95%CI=1.07, 2.18), while larger cohorts (>2,000 patients) showed attenuated risk (HR=1.33 vs. 1.75 in smaller studies). MGC exhibited larger tumors, advanced T stage, and higher risks of metastasis (lymphatic, vascular, peritoneal). CONCLUSION: MGC’s prognostic impact depends on tumor stage and cofactors, not histology alone. Clinical assessment should integrate TNM stage and tumor characteristics, particularly in early-stage disease.