Introduction: Cardiac involvement is a rare unusual localization of Hodgkin lymphoma, as it’s known that primary lymphomas of the heart are rare. They develop primarily in the right atrium, and extend to the pericardium in about one third of the cases. Pulmonary infundibular stenosis secondary to mediastinal mass Hodgkin lymphoma invasion is rare but not impossible especially in relapse cases. Case Report: A rare case of a young adult patient diagnosed with Hodgkin Lymphoma under chemotherapy presents a relapse of his pathology associated with heart failure; predominantly, right heart failure due to extension of the mediastinal mass tumor to the right cavities of the heart causing pulmonary infundibular stenosis which is a rare occurrence. He was put under an intense chemotherapy and symptomatic heart failure treatment with close follow-up after multi-disciplinary discussions including cardiologist, onco-hematologists and cardiothoracic surgeons. Three months later, a significant reduction of the mass was observered. Conclusion : Pulmonary infundibular stenosis secondary to mediastinal Hodgkin lymphoma invasion is a rare entity of secondary tumors of the heart. Multimodal imagery is the key tool for diagnosis. There prognosis depend on multiple factors but generally good in younger adult patients compared to aged individuals.