Hereditary hemorrhagic telangiectasis (HHT) and juvenile polyposis syndrome (JPS) are both relatively rare hereditary disorders. It has been reported that patients with SMAD4 mutations may suffer from both HHT and JPS, defined as JPS/HHT. To improve the understanding and diagnosis of these diseases, we herein report a case of a 17-year-old male with abdominal pain and hematochezia. Low-tension computed tomography (CT) of the small intestine showed intussusception. Combined with the patient's medical history of nasal bleeding and pulmonary arteriovenous fistula (pAVF) embolism, a final diagnosis of JPS/HHT was reached, according to the Curaçao Diagnostic Criteria. The possibility of JPS/HHT should be considered in patients with epistaxis and intussusception.