Portal hypertension leads to pronounced venous collateralization and development of varices. Besides manifest liver cirrhosis, primarily left-sided portal hypertension is causal for the development of gastric varices. We present a case of a 36-year-old female patient with splenomegaly, underlying primary myelofibrosis, and detection of somatic Janus-kinase-2 driver-mutation JAK2V617F. Following first upper gastrointestinal bleeding, isolated gastric varices could be detected as a result of underlying left-sided portal hypertension. Within a few months, repeated life-threatening bleedings with transfusion requirements and frequent hospitalizations occurred. Despite multiple injections of cyanoacrylates, the proven therapy of choice, varices could not be stabilized. Combination of targeted JAK-inhibitor therapy in conjunction with the use of EUS-guided application of coils with subsequent cyanoacrylate injection resulted in acute and long-term bleeding control., (© 2021 S. Karger AG, Basel.)