Effective interventions to improve prognosis in metastatic esophagogastric cancer (EGC) are urgently needed. We assessed the effect of the early integration of interdisciplinary supportive care for patients with metastatic EGC on overall survival (OS).An open-label, phase III, randomized, controlled trial was conducted at Peking University Cancer Hospital & Institute. Patients with previously untreated metastatic EGC were enrolled. Patients were randomly assigned (2:1) to either early interdisciplinary supportive care (ESC) integrated into standard oncologic care or standard care (SC). ESC was provided by a team of GI medical oncologists, oncology nurse specialists, dietitians, and psychologists; patients in the SC group received standard oncologic care alone. The primary end point was OS in the intention-to-treat population.Between April 16, 2015, and December 29, 2017, 328 patients were enrolled: 214 in the ESC group and 114 in the SC group. At the data cutoff date of January 26, 2019, 15 (5%) patients were lost to follow-up. The median number of cycles of first-line chemotherapy was five (interquartile range [IQR], 4-7) in the ESC group and four (IQR, 2-6) in the SC group. The median OS was 14.8 months (95% CI, 13.3 to 16.3) in the ESC group and 11.9 months (95% CI, 9.6 to 13.6) in the SC group (hazard ratio, 0.68; 95% CI, 0.51 to 0.9; P = .021).The early integration of interdisciplinary supportive care is an effective intervention with survival benefits for patients with metastatic EGC. Further optimization and standardization are warranted.