Background: Incidence of gastric signet-ring cell adenocarcinoma (SRCa) is increasing. Linitis plastica (LP) is its typical presentation. SRCa are associated with less chemosensitivity and more peritoneal metastasis (PM). Most consider PM from a gastric SRCa as an end-stage disease. Cytoreductive surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) are highly debated in those indications. Methods: 277 patients treated for gastric cancer with PM by CRS with or without HIPEC in 19 French centers from 1989 to 2014 were included. Diagnosis of an SRCa was based on the presence of isolated carcinoma cells containing mucin. Purpose: to evaluate the impact of CRS and HIPEC in patients with PM from SRCa compared with those with PM from non-SRCa. Results: 188 patients had an SRCa with 55.1 % of LP. One tumor was a LP in the 89 patients with a non-SRCa. Patients with SRCa were more frequently female and younger, with more diffuse PM, undifferentiated and pN3 tumors. There was no difference in perioperative treatments. 124 (66%) patients in the SRCa group and 56 (62.9%) in the non-SRCa group underwent an HIPEC. Median Peritoneal Cancer Index (PCI) was higher in HIPEC sub-groups (SRCa: 7 v 2; non-SRCa: 5 v 1). PM from SRCa was associated with worse survival from surgery. After CRS, with or without HIPEC, 3-year OS was 14% in the SRCa v 38.4% in the non-SRCa (P = < .001). In the SRCa group, HIPEC was associated with better survival on multivariate analysis than CRS alone (median OS: 16.3 v 11 months, HR, 0.526; 95% CI, 0.34- 0.81; P = .003). LP, tumor grade, PCI and adjuvant treatment were independent prognostic factors. In the non-SRCa group, effect of HIPEC was more significant with 3 and 5-year OS of 50.1% and 45.4 v 17 % and 17 % (P = .004). ASA score, PCI and nodal status were independent prognostic factors. Conclusions: PM from gastric SRCa or non-SRCa have distinct prognosis. HIPEC seems a valuable option therapy for resectable PM from SRCa. Concerning PM from non-SRCa, this study is currently the best evidence that HIPEC can offer similar survival rates to non-metastatic tumors on selected patients. NCT:03253939.