BACKGROUND: The rationale behind the use of HIPEC involves targeted elimination of microscopic peritoneal metastasis, a common route for GCa dissemination, thereby improving the overall survival and reducing recurrences. Moreover, the reasoning behind the use of IORT is enhanced loco-regional control and, therefore, reducing recurrence rates. METHODS: From February 2013 to June 2023, all GCa patients who underwent HIPEC plus IORT during surgery were included in this study. Median overall survival (OS) and disease-free (DFS) survival were used to evaluate the efficacy of this treatment strategy amongst GCa patients, along with the rate of occurrence and severity of post-operative complications associated with this treatment strategy. RESULTS: The median OS and DFS were 63 and 87 months, respectively. More than one-third of the patients in our cohort did not develop any post-operative complications. In patients who developed post-operative complications, the median number of post-operative complications was 1 (IQR 1-2). Most encountered complications were Clavien-Dindo (CD) grade II complications (33.33%) and no in-hospital mortality was observed. CONCLUSIONS: This complex, multimodal treatment strategy results in a significantly prolonged OS and DFS when compared to other treatment strategies for gastric cancer patients, with no added morbidity or mortality.