Background: Medical management of advanced GC is mostly dependent on prognostic assessment based on tumor stage (TNM) and clinical patients (pts)’ characteristics, other than HER2 expression. Prognostic and predictive factors are clearly needed, and histotype could be proposed as a surrogate marker of disease biology. Methods: We retrospectively analyzed pts with advanced GC treated with first line chemotherapy (CT) at Oncology Unit of Humanitas Gavazzeni (Bergamo) and Policlinico Gemelli (Roma). Pts were divided in three subgroups according to histological diagnosis: diffuse type carcinoma, intestinal type carcinoma and signet ring cell carcinoma. HER2 positive tumors were excluded from the analysis. The aim of our analysis was to compare clinical outcomes of metastatic GC pts receiving first line CT according to histological classification (overall survival: OS and Progression Free Survival: PFS). Results: We analyzed 170 pts. Histological diagnosis was as follows: 24.1% (n=41) signet ring cell, 54.4% (n=92) diffuse type, 21.1%(n=37) intestinal type. Pts received a fluoropyrimidine-based doublet containing cisplatin, oxaliplatin or irinotecan; in three drugs regimen anthracycline was added. In diffuse type subgroup OS was: 11.3 months with oxaliplatin based CT, 7.3 months in cisplatin and 6.2 months in irinotecan (p=0.0054); PFS was 5.2, 3.5 and 4.4 months for oxaliplatin, cisplatin and irinotecan based CT respectively (p=0.0036). In signet ring cell carcinomas OS was 12.1 months with oxaliplatin 13.9 with irinotecan, and 5.6 months with cisplatin (p=0.04), and PFS was 6.5, 8.5 and 2.9 months in pts treated with oxaliplatin, cisplatin and irinotecan respectively (p=0.0008). Among pts with intestinal type we did not detect any significant difference in term of OS and PFS comparing first line schedules. Conclusions: Based on our results, histology may be used as a simple, costless and easy tool in advanced gastric cancer treatment management. Clinical use of biomarkers (with the exception for HER2) which are being evaluated as prognostic or predictive factors in GC, is still controversial. In this scenario, the prognostic / predictive value of histology could play a significant role in treatment decision making.