BACKGROUND Budd-Chiari Syndrome (BCS) is a relatively rare clinical disorder with a wide range of symptoms, caused by the obstruction of the hepatic venous outflow. The etiology and pathogenesis of BCS vary in different countries and regions. In Western countries, hepatic venous obstruction is the most common type, and its main cause is closely related to the hypercoagulable state of the body. Inferior vena cava obstruction is common in Asia, and its etiology progresses slowly due to the lack of epidemiological data. [3] Here, we report a rare case of BCS associated with the hypereosinophilic syndrome and discuss the possible causal relationship between the two. METHODS The patient was a 33-year-old female with intermittent epistaxis, gum bleeding, and excessive menstrual flow for the past 6 months. The routine blood tests showed elevated levels of eosinophils, and the liver function test showed mildly elevated levels of γ-glutamyl transpeptidase and alkaline phosphatase, and abdominal ultrasound showed hepatosplenomegaly and suspicion of intrahepatic arteriovenous or arteriovenous-portal fistula. METHODS Finally, through the improvement of bone marrow aspiration, digital subtraction angiography and gene detection, the diagnosis of BCS combined with hypereosinophilic syndrome was confirmed, and JAK2V617F mutation was highly associated with it. METHODS The patient received endovascular stent implantation and regular oral rivaroxaban anticoagulation therapy after operation. RESULTS Seven months later, enhanced computed tomography (CT) of the hepatobiliary showed that the hepatic bruise-like changes were significantly reduced compared with before, and the right hepatic vein and the right perihepatic vein stent were left in place with a good filling of contrast in the stent. CONCLUSIONS The patient, in this case, was finally diagnosed with BCS combined with hypereosinophilic syndrome, and to our knowledge, such case reports are rare. Our case report suggest an association between BCS and hypereosinophilic syndrome, but relevant studies are minimal, we hope to conduct larger and higher quality studies on these patients in the future, to provide new directions and basis for the etiology and pathogenesis of these diseases, as well as provide new targets and ideas for clinical treatment.