The multi-institutional registry in this study evaluated the outcome after cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with peritoneal metastases (PM) from small bowel adenocarcinoma (SBA).A multi-institutional data registry including 152 patients with PM from SBA was established. The primary end point was overall survival (OS) after CRS plus HIPEC.Between 1989 and 2016, 152 patients from 21 institutions received a treatment of CRS plus HIPEC. The median follow-up period was 20 months (range 1-100 months). Of the 152 patients, 70 (46.1%) were women with a median age of 54 years. The median peritoneal cancer index (PCI) was 10 (mean 12; range 1-33). Completeness of cytoreduction (CCR) 0 or 1 was achieved for 134 patients (88.2%). After CRS and HIPEC, the median OS was 32 months (range 1-100 months), with survival rates of 83.2% at 1 year, 46.4% at 3 years, and 30.8% at 5 years. The median disease-free survival after CCR 0/1 was 14 months (range 1-100 months). The treatment-related mortality rate was 2%, and 29 patients (19.1%) experienced grades 3 or 4 operative complications. The period between detection of PM and CRS plus HIPEC was 6 months or less (P = 0.008), and multivariate analysis identified absence of lymph node metastasis (P = 0.037), well-differentiated tumor (P = 0.028), and PCI of 15 or lower (P = 0.003) as independently associated with improved OS.The combined treatment strategy of CRS plus HIPEC achieved prolonged survival for selected patients who had PM from SBA with acceptable morbidity and mortality.