e14004 Background: Gastrointestinal (GI) cancers are amongst the leading causes of cancer-related death worldwide. GI cancers with brain metastasis on presentation are rare; however, the oncologist will intermittently encounter such patients. Unfortunately, there is a paucity of data to inform the prevalence and prognosis of GI cancers with brain metastasis, especially in light of therapeutic developments in the past decade and whether that might have influenced the survival. In this study, we measured the prevalence of brain metastasis secondary to primary GI malignancies at the time of diagnosis, the observed median survival, and Kaplan-Meier 2-years overall survival. The aim is to highlight the burden and prognosis of this population. Methods: We queried the Surveillance, Epidemiology, and End Results (SEER) Program 18 registry (2010-2018) database. We identified the total number of patients and patients with brain metastasis at the time of diagnosis for the following gastrointestinal cancers: esophagus, stomach, pancreas, colon, rectum, liver, intrahepatic biliary duct, and gallbladder. We obtained the prevalence, the observed median survival, and the 2-years survival using the Kaplan-Meier method. Results: The total number of cases, prevalence, median survival, and 2-years overall survival are shown in the table. The prevalence of brain metastasis at diagnosis was highest for esophageal cancer at 1.41%, followed by stomach 0.52%, and gall bladder 0.37%. The lowest incidence was small intestinal cancers at 0.13%. The median survival was short, ranging between 2 to 4 months for all studied cancers except for the small intestine and rectum at about six months. Kaplan-Meier 2-years survival was highest for the small intestine at 17%, and the worst was gallbladder, where no one survived at the end of the 24 months. Conclusions: Brain metastasis at the time of diagnosis of GI cancer remains rare. However, its presence portends an abysmal prognosis of 2-4 months. This study helps to inform the practicing oncologist of the current prevalence and prognosis of GI malignancies with brain metastasis on presentation. In addition, these findings encourage prompt involvement of palliative care, setting realistic expectations, and discussing goals of care once such a grave diagnosis is made.[Table: see text]