Idiopathic pulmonary arterial hypertension is a rare disease in children. We report a case of a 2-year old boy admitted to the intensive care unit of our hospital for severe dyspnea and epistaxis. Laboratory investigations showed hemolytic anemia with schizocytes and severe thrombocytopenia. Cardiac investigations diagnosed supra-systemic pulmonary arterial hypertension, which was refractory to maximal medical treatment. On evolution, he had several cardiac arrests and finally died 8 days after admission. Autopsy was performed and showed typical lesions of idiopathic pulmonary hypertensive arteriopathy characterized by plexiform lesions of the interlobular arteries containing numerous disseminated intravascular microthrombi. The rest of the family was screened, DNA was stored, and genetic study of BMPR2 was planned.