Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but serious, sequala of acute pulmonary embolism. Symptoms can be subtle and non-specific and the prognosis is poor if severe pulmonary hypertension (PH) and right ventricular dysfunction are present. While PH-targeted therapies are often used, there is only one FDA approved therapy, and only for disease that is deemed inoperable. The greatest chance for potential cure and long-term survival is surgical pulmonary endarterectomy. We report a 6-year-old male with a history of asthma and two unprovoked deep venous thromboses who presented with syncope. Chest x-ray showed cardiomegaly and an echocardiogram showed severe PH with severely decreased right ventricular (RV) function. Ventilation-perfusion scan showed mismatched perfusion defects involving the right lower lobe, and CT of the chest showed right lower lobe subsegmental pulmonary thrombus, suspicious for chronic thromboembolism. Given his clinical presentation and the severity of his right ventricular dysfunction, he was started on ambrisentan, sildenafil and subcutaneous treprostinil. Bilateral pulmonary endarterectomy was performed with resection of level 2 to 3 disease and he was successfully weaned off all PH therapy. Four months post-op, he is clinically asymptomatic and his echo shows normal RV function without PH. In conclusion, CTEPH is a rare but likely underdiagnosed disease process in pediatrics. Clinicians should have a high index of suspicion for at risk patients with unexplained dyspnea. Even if right ventricular dysfunction and severe PH are present, surgical pulmonary endarterectomy can be performed successfully in young children.