The authors report a case of cardiac malignant non-Hodgkin lymphoma. The initial clinical presentation suggested recurrent angina in a patient who had undergone angioplasty of the left anterior descending artery two years previously. Echocardiography showed severe left ventricular dysfunction with apical and septal akinesia and also allowed visualisation of two oval masses in the right ventricle without dilatation of the right heart chambers. Transoesophageal echocardiography confirmed these abnormal echos which corresponded to tumour invasion of not only the right heart chambers but also the interatrial septum, the left atrial appendage and the descending thoracic aorta. Histological diagnosis of lymphoma was made from an excision biopsy of a mass in the calf muscle. The post-mortem examination confirmed the presence of a highly malignant T-cell non-Hodgkin lymphoma. The patient rapidly deteriorated and died during the first session of chemotherapy.